Terraria Boss Ideas 10 [1-20]

Well darn, Boss Ideas 10 exists now, I guess

As usual this is not a guide, it's just here for formatting purposes and for consistency's sake

Few differences now which will be explained in the news section, but I'll keep the description short

Anyways, lets go :)

[News Corner]

1. Mods
So, I've already stated before, I'm helping out some mods now. Helping Reality as a concept designer and spriter, and basically the same for Technological Terror, another mod I began helping out recently as well. Also assisting (potentially) with others too, so I've got quite a few things to keep me busy outside of Boss Ideas now (:P)

2. Themes
Yeah, believe it or not, themes. Weird flashbacks to that section from Boss Ideas 4 aside, Phantasmental has actually made a few of these themes by seeing these bosses' designs and just wanting to make them, so a big thanks there. Will also link any I can if they're up on YouTube by the time this is made.

3. 1.4
The most obvious change. 1.4 now means Master Mode; so based on what Master Mode brings will affect any more additions to these bosses. Some might be rough at first as I become accustomed to any other important Master Mode changes, but we'll get there :P

Anyways, away we go!

[Important Buffs]

So I don't have to write out their effects within each individual boss anymore... plus for anyone who just wants to see sprites they can just skip this, I guess?

Red Lightning:
Users: Scrapwyrm, Bumbleknight, Crystal Wraith
Effect: Deals 5 damage per tick, which is increased to 8 when moving. Also reduces movement speed by ~8% and defence by 5.
Tooltip: A powerful static charge fills your body.

Heavy Gravity:
Users: Fairy King's Behemoth, Crystal Wraith, Revenant
Effect: Reduces max flight time and speed by ~67%
Tooltip: The gravity here feels stronger...

Energy Surge:
Users: Fairy King's Behemoth, Elder Cosmic Dragon, Twisted Cosmic Dragon, Ebony Flame, Crystal Wraith
Effect: 15 damage per second, reduces defence by 20, damage reduction by 5%, and damage dealt by 8%
Tooltip: A powerful surge of energy overwhelms you!

Ethereal Affliction:
Users: Revenant
Effect: Deals 15 damage per second and increases damage taken by 10%. If hit by an attack that would inflict the debuff again whilst applied, The effects are enhanced for 3-5 seconds to 30 damage per second and +15% damage taken.
Tooltip: Otherworldly presences haunt you

Tongue Leech:
Users: Revenant
Effect: Deals 20 damage per second. Applied indefinitely until Revenant's tongue is killed.
Tooltip: Your spirit seeps away...

01 - Sentinel

Appearance: A 1-eyed humanoid robot in a cloak. Her face and the cloak are a dark blue and her 'hair' a dark purple. She also appears to wield a fencing sword.

Summon: Use the UV Beacon anywhere in the world. Additionally, once Post-Moon Lord it has a chance of spawning by itself very rarely, though with increased damage.

Fought: Hardmode
Specification: Post-Plantera
Special?: Can summon itself later
Progression: No...?

Stats:
Health: 25,600 (34,750) (44,307)
Attack:
-55 (105) / 95 (155) (Melee)
-50 (100) / 92 (150) (Sabre Scythe)
-46 (93) / 88 (142) (Laser Discs)
Defence: 20
[Attack pool 1 is for Hardmode, Attack pool 2 is for Post-Moon Lord]

Attacks:
Sentinels will pursue the player at high speeds, running along the ground and performing mid-air dash attacks in order to reposition themselves for an attack. Usually, a Sentinel will only go around 3-5 seconds before beginning another attack, usually on the shorter end for Expert mode.
-She may levitate near the player and launch a flurry of 'laser disc' projectiles at them which pass through blocks
-She may perform a wide, arcing slash with her fencing sword, creating a large crescent-shaped shockwave towards the player called the 'Sabre Scythe'. The slash also extends her melee hitbox. (In Expert Mode the Scythe also has mild homing properties and will arc towards the player.)
-She may lunge at the player with her sword. The distance this attack travels increases as a Sentinels' health decreases.

Defeat:
Falls to the floor, stays motionless briefly, and then explodes into a burst of light blue particles; leaving no gibs. The particles are similarly-coloured to a Magic Mirror's.

Drops:
May drop her sword, a tome that fires laser discs rapidly, or her cloak that grants the player a long-ranged dash. Additionally, has a rarer chance to drop an accessory that grants the user a Sentinel minion that will attack nearby enemies with sword strikes and laser discs. In Expert Mode it drops the Sentinel's Heart; an accessory that can be combined with different Soul types to provide the player with buffs and also transforms the player into a Sentinel (Solely vanity).

Lore:
Despite their seemingly-fragile frames, they are highly-efficient bodyguards for anyone who pays for their services. Despite being mute machines they seem to have emotions, though put them aside when it comes to combat. The person who produces them is currently unknown...

Hints:
-Sentinels are generally fast and dangerous, so dashes and the RoD are very useful.
--The Master Ninja Gear, especially, is good since it's a Post-Plantera accessory with a dash and an additional dodge chance
-Sentinels cannot spawn when the player is in a town, in space, or in the underworld once the player is Post-Moon Lord.

Extra Info:
-While Sentinels are mechanical, they are usually addressed as female because their body shape is considered generally feminine (not that it can be seen with their cloaks in the sprite, though...)
-The Sentinel has a theme, made by Phantasmental: https://soundcloud.com/phantasmental/sentinelscombat
https://youtu.be/GPAozdBA2eE
-The Sentinel has a chance of appearing in Technological Terror, due to its theming, but has yet to be confirmed.
-The Sentinel does technically have animations for most of her attacks, something not usually seen from Boss Ideas, due to her possible mod addition requiring them
[Added: 20/05/20]

02 - Cadmar Slime's Revenge

Boss (still) dedicated to Cadmar


Appearance: The Cadmar Slime, back from a previous page. Its colouration is move vivid, and its original wizard had has been modified; with a crown-like brim and numerous gemstones built into it.

Summon: Use the Slime Stone at the surface. The biome it is used in is unimportant, because as long as the player is at the surface the summoner will work. The boss only despawns if you go too far away and is generally unaffected by biomes.

Fought: Pre-Hardmode
Specification: Post-EoW/BoC
Special: Returning Boss
Progression: No

Stats:
Health: 3,200 (5,000) (6,375)
Attack:
-30 (55) (Melee)
-25 (47) (Magic Blast)
-15 (25) (Sparks)
Defence: 4

Attacks:
Cadmar's main attacking method involves hopping at the player quickly for a time, and then using one of a few magic attacks. If needed, it can jump higher or ignore some solid blocks to reach the player if deemed necessary.
-He may pull out a wand similar to the Gold Staff and launch several energy bolts at the player (These are noticeably faster in Expert Mode).
-He may jump high into the air above the player and slam down into the ground. This attack will also release sparks that deal minor damage.
-[Expert Exclusive] He may disappear before a large group of slimes rush in from either the left or right. Most will be invulnerable green slimes, but Cadmar will also be amongst them. They follow similar rules to Cadmar itself regarding blocks, and continue moving in the same direction. The attack ends with Cadmar jumping out from the fray as all the green slimes vanish again. All slimes here deal Cadmar's contact damage.
Cadmar's attack speed will increase marginally as it loses health, with more substantial changes in Expert Mode.

Defeat:
The crown/wizard hat will be knocked off his head and he will be sent bouncing away based on what direction the attack that defeated him was moving in. This bouncing Cadmar is purely aesthetic and cannot be interacted with. If stuck on blocks it will eventually begin to pass through them.

Drops:
Will solely drop magic items, such as a tome and a magic staff. In Pre-Hardmode it can drop a summon staff that summons green slime minions, though later in Hardmode this drop is replaced with a stronger version that instead summons winged slimes instead. In Expert Mode it drops the Slimy Gem which increases magic and summon damage mildly, as well as boosting the damage of all slime-like minions. This can also be combined with the expert items from the vanilla Slime bosses.

Lore:
Banished from the King Slime's court for 'reasons', the Cadmar Slime has promoted itself to a king-like status. Using any magic at its disposal, it plans to eventually overthrow the King Slime, seemingly unaware that another royal slime exists.

Hints:
-Fighting Cadmar in an open space is recommended, since it can ignore blocks and thus can't be cheesed using solid barriers
--Similarly, it risks getting stuck on terrain and performing one of its less predictable actions otherwise; adding unnecessary difficulty
-The Hardmode summon staff is good for early Hardmode since Cadmar itself doesn't actually get buffed. This also partners with its Expert accessory for some strong early Hardmode minions.

Extra Info:
-The Cadmar Slime has appeared as a boss previously in Boss Ideas 5. It had a shapeshifting ability back then, but that didn't return in the remade fight.
--However, its general role of 'slime wizard' still remains
-The Cadmar Slime is based on Cadmar, who had commissioned the original boss. At the time of writing this, it is also his profile picture.
[Added: 20/5/20]

03 - Scrapwyrm

Appearance: A rusted mechanical worm. Its body segments are almost beetle-like, separated into individual plates, with only a few greyish pieces seen between them. Its jaws are curved inwards and its tail segment has two parallel-running blades that gain an electrical charge from a gemstone positioned between them.

Summon: Use the Rusted Clump at night. The boss will enrage during the day, increasing movement speed and attack frequency. The boss will pursue the player if they flee at increased speed, meaning the only ways to despawn it are to either die or leave the world.

Fought: Hardmode
Specification: Post-Golem
Special?: No
Progression: No

Stats:
Health: 100,000 (172,850) (220,384)

Attack:
-100 (220) (Melee)
-62 (112) (Magnet Sphere)
-75 (130) (Magnet Bomb)
Defence: 20

Attack:
-70 (124) (Melee)
-58 (105) (Spark Bullet)
Defence: 28

Attack:
-85 (180) (Melee)
-70 (124) (Magnet Blast)
Defence: 40
[All of the boss' attacks inflict Red Lightning - 33 (50)%]

Attacks:
Mostly moves like most worms; burrowing at high speeds. If the player is too high to reach it is allowed to fly, though acts moreso like a Wyvern temporarily than like the Destroyer does. It telegraphs its ranged attacks based on what orbs on its body begin to glow.
If the head glows:
-It may launch an electrical orb that shoots sparks at the player as it travels (In Expert Mode the sparks are replaced with thick 'bolts' like the Cultist's lightning orbs).
-It may launch several chunks of electrified metal that hang in the air. If the player gets near them they begin to chase the player, exploding either on contact or after travelling too far (and in Expert they move faster).
If the body segments glow:
-It will launch a barrage of laser-like 'spark bullets' at the player. All segments that illuminate will launch at least one, though it maxes out at 3 shots maximum from any single segment. The number is random (though usually goes for 2-3 in Expert).
If the tail segment glows:
-The tail will rapidly fire large red projectiles at the player in succession. They are aimed at the player, with the aim readjusted each shot, and they pass through blocks.

Defeat:
Explodes into fiery gibs

Drops:
Will drop a sword based on one of its jaws, a magic staff utilising its tail's crystal, a summoner staff that summons a beetle-like minion based on its head, and a gun that fires electrified tracer rounds. Will also drop Rusted Shell Pieces; materials used to either make or upgrade other weapons and armour. In Expert Mode it additionally drops an accessory that provides the player with a damaging aura that grows the lower health they have left.

Lore:
A machine rejected by its creator as they moved to greater projects. Exposed to the elements, its body has been overcome with rust. How it looked in its prime is unknown.

Hints:
-Unlike bosses like the Destroyer, simply getting to higher ground is actually arguably a bad idea. As it takes on more Wyvern-like flight to get back to the player, keeping it on a lower plain is incredibly hard to do and will cause its AI to become more unpredictable.
-Having some cover made from solid blocks can be helpful for blocking the boss' more dangerous attacks, such as the bullets and magnet sphere attacks.

Extra Info:
-The boss shares its debuff with only 1 other boss seen later
-The boss was originally made for Technological Terror, much like the Sentinel but, unlike her, was scrapped
[Added: 21/5/20]

04 - Cosmic Blacklight

Appearance: Blacklight, though powered-up seemingly with a strange cosmic energy. Its formerly silver and gold body is now a shiny brown with orange crystals aligned beneath the mirror. Its formerly shadowy wings have now been replaced with a scenic view of space, which has similarly happened with the mirror part.

Summon: Use the Cosmic Mirror in space. If the boss is taken out of space it will gain increased movement speed and defence, but won't despawn. If the player gets too far away, however, it can still despawn.

Fought: Post-Moon Lord
Specification: Post-Moon Lord
Special?: Returning Boss
Progression: Later Bosses

Stats:
Health:
-500,000 (765,000) (975,375) (Blacklight)
-50,000 (76,500) (97,538) (Clones)
Attack:
-200 (350) (Blacklight Melee, Clone Melee)
-188 (332) (Phantasmal Sphere, Cosmic Freeze)
-175 (320) (Cosmic Wave)
-255 (450) (Blacklight Cosmiviscerator)
-230 (400) (Clone Cosmiviscerator)
Defence:
-45 (Blacklight)
--135 (Blacklight - Outside Space Biome)
-90 (Clones)

Attacks:
Phase 1:
Stays stationary when attacking, though will teleport to reposition itself. After every 3rd teleport it will spawn a clone. Clones look like Blacklight, though are smaller and lack the wings the true one has.
-Blacklight can launch large orbs of energy called Phantasmal Spheres at the player, with smaller orbs orbiting them. These large orbs have a mild homing effect, like Skeletron's skulls, and both the small and large orbs deal the same damage and pass through blocks. Usually up to 5 of these can be launched in succession, with only 0.6 (0.45) second gaps between them.
-Blacklight can launch a flurry of projectiles at the player. These move toward the player, but do so in a sine wave motion. These projectiles, called Cosmic Waves, have their waves' peaks made larger as Blacklight loses health, though they are just as fast.
-Blacklight can create an extra clone (2 extras) instead of attacking. This also has a cooldown where Blacklight itself remains motionless for a few seconds after spawning them.
All clones will perform the same attack pattern of firing a Cosmic Wave at the player, waiting a second, then teleporting again.
Once down to 75% health it will transition to its 2nd phase.
Phase 2:
Blacklight will fly near the player in this phase, not attempting to melee them but instead just trying to remain close. It still occasionally teleports, though less frequently, but now every second (every teleport) will spawn a clone.
Blacklight retains all its attacks from Phase 1, but he also gains two new ones:
-He may fly just above the player, gathering energy. After a few seconds he will stop and, a short time after, creates a massive explosion of cosmic energy around itself. If the player doesn't get out of the way fast enough it will hit them.
-Blacklight may spread out its 'wings', staying motionless very briefly. After this, several small orange clusters of sparkles will begin appearing randomly nearby. These clusters can't hurt the player themselves, but after a short delay they will all explode into large icy crystals. These crystals remain in place for a short time (longer in Expert) and deal contact damage until they despawn.
The clones get a new attack as well. If they remain active for too long, or if Blacklight uses its Cosmiviscerator attack, they will all slowly begin flying towards the player charging energy as well. Their versions are smaller and, after use, the clone shatters.
Once at 20 (30)% health it enters its 3rd and final phase.
Phase 3:
Blacklight now flies toward the player as opposed to just randomly near them. It retains all its previous attack in this phase, though one other change is that now all teleports will spawn clones.
Clones will attempt to use the Cosmiviscerator attack after only a few seconds, so they often don't last very long.

Defeat:
Its wings shatter and the mirror cracks. Blacklight disappears into a cluster of particles shortly after. A status message "Cosmic Energy seeps into the ground below" appears, allowing more bosses to be fought.

Drops:
Drops lots of Cosmic Shards; used in a lot of materials later-on and in upgrading numerous items. In terms of weapons it can drop a summoner staff, a sword, a 'true melee' sword, a bow, and a magic tome. In Expert Mode it also drops the Cosmic Shield that causes the player to explode violently on death to deal massive damage to nearby enemies, reduces respawn time slightly, and grants the player more max mana.

Lore:
After a previous defeat, Blacklight lay dormant in orbit. After many days of exposure to a strange, harsh cosmic energy, it was reborn as this.

Hints:
-If possible, it is recommended to deal with the clones as soon as possible. Having too many around may cause issues for the player due to the space they take up and their additional projectiles.
-Having a RoD around is, as ever, very helpful. It allows the player to escape the Cosmiviscerator even if they otherwise wouldn't have, dodge its homing attacks easier, and generally just keep away from it better in the third phase.
--It can also be a lifesaver if the player finds themselves in a bad position during the Cosmic Freeze attack, where they may otherwise be forced to take damage due to the ice crystals' spawning locations.
-Dashes can allow the player to escape a Cosmiviscerator blast if not moving, or the player can avoid it by continuing to move away from Blacklight throughout the entirety of the charge and explosion.

Extra Info:
-Despite being a remake of Blacklight, it shares little with the original fight. It lacks an arena, its attack pool is broader and less limited, and even the minions themselves spawn and act differently.
--The main similarities left are Cosmic Freeze being similar to another attack from before, and its lack of movement aside from teleports in Phase 1.
-Delly makes some real cool palettes, and this is one of them (if not already outdated by the time this is released).
[Added: 21/5/20]

05 - Slime Dragon

Appearance: A large, gelatinous mass wired up to a jetpack-like machine. Additional machinery can be seen through its transparent body, including a spherical orb with lights inside its 'head'.

Summon: Use the Oozing Core anywhere in the world. The boss can despawn if the player gets too far away, like most bosses, but is unaffected by biomes and time.

Fought: Hardmode
Specification: Post-Golem
Special: No
Progression: No

Stats:
Health:
-50,000 (74,500) (94,988) (Slime Dragon)
-200 (340) (434) (Booster Slime)
Attack:
-70 (120) (Melee, Lightning Orb)
-55 (100) (Slime Globules, Booster Slime Melee)
-85 (150) (Chest Laser)
Defence:
-35 (65) (Slime Dragon)
--10 (5) (Slime Dragon - Recovering)
-10 (Booster Slime)

Attacks:
The Slime Dragon moves fast and is highly aggressive. It uses attacks with little downtime and its movement speed is very high (Faster in Expert). It has a wide assortment of attacks at its disposal:
-It can fly horizontally to the player before dashing at them, attempting to ram the player
-It can fly near the player, usually diagonally to them, while launching large globules of slime at them. These explode on contact with solid blocks into an explosion of slime.
-It can hover around 20 blocks above the player, raining down globules
-It can dash above the player, summoning up to 4 Booster Slimes
-It can dash back and forth above the player up to 3 times, dropping globules down randomly.
-It may summon an orb that shoots lightning at the player, similar to LC's
-It may charge up a massive deathray from its chest. Once ready it will fire downward from above the player, chasing the player as they move to avoid it. This attack is only used below 50 (65)% health.
After using 3 (4) attacks, it will stop for a time and recharge. In this 'recovering' state it is immobile, not attacking the player, and its defence drops significantly. After a few seconds it will have recharged and begin attacking again.
Boosters Slimes simply fly after the player using mini jetpacks. Once damaged enough they explode into gibs, unlike Slimers.

Defeat:
Parts of its body will burst, and the jetpack partially explodes. After a short time recuperating, the Slime Dragon slowly flies upwards until it despawns. It drops loot the second its health reaches 0.

Drops:
Drops an upgraded variant of a slime staff that summons Booster Slime minions, a staff that launches high-velocity slimeballs, a laser cannon, and a jetpack accessory. In Expert it also drops a light pet that is basically a slime in a helmet and armour similar to the Slime Dragon's.

Lore:
Created due to the rumours of a mechanical slime in an attempt to rival or dethrone it. The menace was allowed to freely roam the world in search of its opponent, but to no avail. Now it simply answers the call of any challenger who thinks itself tough enough to face it.

Hints:
-Speed is key throughout most of the fight. Dash attacks are common and it is capable of easily bombarding the player with explosive projectiles, so the player will need speed to dodge the attacks
--Teleports and dashes are, as ever, highly valuable during the fight. Dashes are less useful due to the boss having very high horizontal mobility and numerous 'projectile rain' attacks.
-Just keep running in one direction to avoid the deathray in the easiest way possible.
-Dealing with the Booster Slimes earlier on is recommended since they can get in the way of dodging, which can cause the player to be caught by the Dragon's more powerful attacks such as the deathray

Extra Info:
-Its summoning weapon is also buffed by Cadmar Slime's Expert Drop, which can be used to give the minions additional strength alongside a summoner set.
-The Slime Dragon was put forward to TT, and was eventually accepted as a boss. This means it may be the first boss to truly have an 'actual' fight from Boss Ideas.
-The Slime its lore refers to is likely Slimey, being as he's a recurring character who loosely fits the description of a 'powerful mechanical slime'.
- Phanta has also created a theme for the Slime Dragon: https://soundcloud.com/phantasmental/slime-dragon
https://youtu.be/u6m3e_Rbec0
[Added: 21/5/20]
[Updated: 28/6/20]

06 - Sharlteron

Appearance: A skeletal, shark-like monster with a body composition similar to Duke Fishron. Its entire skeletal body is a strange dusty orange colour. Despite being shark-like, its head shape is unusual; with a large solid bone near the snout and 'spikes' above its eyes and on the back of its head.

Summon: Use the Cursed Skull in the desert during the day. Sharlteron will enrage if taken out of the desert for too long, boosting its movement speed and damage until returned to the desert. At nighttime it will be enraged until day breaks again. It despawns if the player dies or gets too far away, as with most bosses.

Fought: Hardmode
Specification: Post-Golem
Special: Reference boss, pseudo-joke boss
Progression: No

Stats:
Health:
-48,500 (70,000) (89,250) (Sharlteron)
-1,000 (1,850) (2,359) (Sharlter Clones)
-999 (999) (1,274) (Sharlter Bones)
Attack:
-88 (130) (Sharlteron Melee)
-80 (120) (Sharlter Clone Melee, Sandnado)
-100 (145) (Giant Sandnado)
-75 (110) (Sandstone Spike, Sand Skull)
-20 (35) (Sharlter Bones Melee)
Defence:
-55 (Sharlteron)
-65 (Sharlter Clones)
-99,999 (Sharlter Bones)

Attacks:
Phase 1:
Will dash at the player 3 times before attacking. All 3 dashes act differently, but the order is consistent: the first dash is a long-distance dash at the player, the 2nd a quick dash with a lot of vertical movement but lacking in horizontal movement, and the third has horizontal distance but lacks vertical movement. After the third dash it will attack:
-Will perform a loop, summoning a bunch of sand skulls. These slowly chase the player, but disintegrate after travelling far enough
-May summon a sand tornado beneath itself. These don't have Sharkrons in like the Duke's, but they do linger for longer before disappearing.
-May perform another charge at the player, creating numerous sandstone spikes that are launched randomly. They are affected by gravity.
At 50 (70)% health he will enter his 2nd phase.
Phase 2:
Dashes at the player 5 times now; with the first 3 being the same, and the final two both aimed directly at the player. It retains all previous attacks, but at the end of every second attack will spawn a Sharlter Clone; a skeletal shark with a sandnado-like tail that chases the player while occasionally launching sand skulls at them.
It will also summon a Giant Sandnado directly beneath itself as it enters the 2nd phase. This remains throughout the whole fight, only despawning once Sharlteron is gone.
Sharlteron also gains new attacks in this phase:
-May disappear, then re-appear near the player; dashing at them. This dash also creates either sandstone spikes or sand skulls, randomised per dash, and this dash can happen up to 3 times in succession.
-May continuously loop, pulling the player into a sand vortex. The vortex does no damage, but Sharlteron can hit the player still. The pulling power of the vortex is immensely large, throwing off player movement from great distances.
[Expert Mode exclusive Phase]
If down to 20% health in Expert Mode, it will enter a third phase.
At the beginning of this phase, it summons a 2nd giant sandnado beneath it, which is also semi-permanent like the first.
It gains no new attacks, though a sandstorm will be summoned during the phase transition, and at Sharlteron teleports at the end of every attack cycle near the player ready for the next series of dashes.

Defeat:
Sharlteron's body and all the clones explode into gibs, leaving only the head. The head, called 'Sharlter Bones', slowly hops towards the player, trying to bite them whilst mocking them with overhead dialogue. It has knockback resistance so low almost any attack will launch it over the horizon, which is important to note since it regenerates health so fast you can't kill it*. It drops loot once the body is destroyed; the head drops nothing.

Drops:
A summon staff that summons a mini Sharlteron using 3 minion slots, a Light Disc-like stackable boomerang, a sword, flail, and a magic staff. Can drop a set of wings that are quite fast and become faster in sandstorms and provide immunity to the sandstorm's wind debuff. In Expert Mode it drops another accessory that grants defensive buffs that get stronger at lower health and, on death, drops a skull that protects the player's money so it cannot be stolen by enemies.

Lore:
An ancient and seemingly-immortal entity. It has been disgraced many times, leading to its grumpy temperament and rehousing to the more quiet desert where it now resides.

Hints:
-While it would seem similar to Fishron due to its appearance, similar strategies won't always work since the phases are different, the tornadoes act different, and the minions are permanent as opposed to just cannon fodder.
-Dashes are good for dodging, but be aware of its horizontally-adept charge and the sandstone spikes' trajectories.
-Just moving away from the sand skulls consistently will work for avoiding them, as they are fairly slow

Extra Info:
- https://soundcloud.com/phantasmental/sharltonbones - Yes! Believe it or not, this is actually one of the bosses who actually has a theme! (Yes I know the name's different on there, but same guy). Credit to Phanta for making it, cool dude :P
-Sharlteron started as a joke, based on something some devs had found over in the Ancients Awakened and Reality discords, and eventually made into a more serious boss.
--The 'final phase' consisting of just its head is a reference to its originally silly nature
[Added: 27/5/20]

07 - Bumbleknight

[In memory of the old Bumblebirb]


Appearance: A bumblebirb, donning a set of tan armour. It only covers the top half of its body, part of the wing, and its head due the birb's plump physique.

Summon: Use the Birb Armour Plating in the jungle. The item itself is a rare jungle enemy drop not referenced by anything, making it a potential 'secret boss' candidate. It can be taken outside the jungle without penalty, but can still be despawned by dying or getting too far away from it.

Fought: Post-Moon Lord
Specification: Post-Moon Lord
Special: Bumblebirb, 'Secret' boss
Progression: No

Stats:
Health: 227,500 (364,000) (464,100)
Attack:
-160 (270) / 185 (310) (Melee)**
-200 (332) / 240 (384) (Volt Tackle)*
-130 (220) / 160 (277) (Lightning Spear)**
-150 (256) / 175 (295) (Feather Clump)*
Defence: 65

[Attack range 1 is for Phase 1, Attack range 2 is for Phase 2]
[*All of the following attacks are capable of inflicting Red Lighting - 50 (66)%]
[**All of the following attacks only inflict Red Lightning in Phase 2, same rates as above]

Attacks:
Phase 1:
Flies after the player at a moderate pace, though is relatively slow compared to similar bosses in progression. Will use a range of attacks at random, but frequent, intervals:
-May surround itself will a sphere of red electricity, do a small loop to align itself with the player horizontally, and dash at them at high speeds. The sphere has a hitbox as well, not just the Birb, and the attack does damage far greater than its regular contact damage
-It may dash back and away from the player before launching a flurry of sharp, spear-like electrified feathers at the player. These all have a mild homing effect and move at high speed, though cannot pass through blocks and eventually lose their homing effect.
-It may perform a large loop around the player, leaving clumps of electrified feathers randomly as it performs the loop that hang in-place for a while. These eventually explode into large bursts of electrical energy, dealing damage even in dormant state.
Once down to 40 (55)% health, it transitions to its 2nd phase
Phase 2:
The Bumbleknight now has visible red electrical particles coming off of it, and all of its attacks can now inflict Red Lightning as opposed to just 2. Its general movement speed is faster and it uses its attacks more frequently.
While it gains no new attacks, all its previous attacks receive changes:
-The volt tackle attack's loop is now faster, and it no longer needs to line up with the player at all; being able to charge at the player from wherever.
-The lightning spear attack now has the Knight dash at the player as opposed to moving away, spawning the spears as it moves. The spears' properties remain the same.
-The feather clump attack now has the Knight loop twice around the player, meaning roughly twice the amount of clumps. Additionally, they are drawn to the player slightly, moving toward the player at speeds based on their distance from it. Their explosions are also a little larger.

Defeat:
The Knight flaps around panicked for a moment, chirps angrily, then flies upwards; dropping its loot after it begins its ascent.

Drops:
A flail based on its feather clumps, a yo-yo that is essentially a mini Bumblebirb on a string, a throwable javelin, a tome that launches homing spear-like projectiles, and a laser rifle that counted as a ranged weapon despite using mana. In Expert Mode it additionally drops an accessory that boosts the damage of melee weapons without projectiles and allows them to launch homing sparks when used.

Lore:
Believed last of its kind, taken in by Royal Guardians for its protection. Fitted with a durable, if makeshift, armour it still frequently revisits its old home of the jungle.

Hints:
-Circling the boss is, in general, one of the best ways to combat it. As it shares many similarities with the Bumblebirb/Dragonfolly still, such as the loss of speed when turning.
-Dashes and teleports are, as ever, useful. However, its Phase 1 'volt tackles' cannot be dashed out of due to them being horizontally-moving attacks.

Extra Info:
-This boss is basically just a homage to the Bumblebirb; a Calamity boss that got reworked into the Dragonfolly due to the mod's serious nature that the Birb contrasted heavily with.
--Remnants of the Bumblebirb/Dragonfolly still remain in this fight, either directly (such as its health and design), or indirectly (such as drop similarities and the lightning spears)
-Additionally, 'Volt Tackle' is a reference to a signature move of the Pikachu family in Pokemon
[Added: 27/5/20]

08 - Solar and Luna

Appearance: 'Twin' mages; one representing the sun and the other the moon. Solar is a yellow and orange fire elemental with a ponytail and a half-cape, while Luna is a blue ice elemental in a dress and a shorter half-cape over her other shoulder.

Summon: Use the Celestial Seal. Depending on the time of day it is used one of the two will be empowered, or if used at 4:30 AM or 7:30 PM specifically both will be for extra challenge. Whenever it is used, the time will be frozen throughout the boss battle. They only despawn if the player dies; chasing the player via teleportation across the map if needed.

Fought: Hardmode
Specification: Post-Golem
Special: Fight elements based on summon time
Progression: No

Stats:
Health:
-60,000 (90,000) (114,750) (Luna)
-70,000 (105,000) (133,875) (Solar)
-100 (185) (236) (Constructs)
Attack:
-70 (130) / 90 (152) (Melee)
-80 (142) / 130 (180) (Fusion Bolts)*
-65 (123) / 80 (139) (Flare/Frost Projectiles, Construct Melee)
-84 (147) / 110 (167) (Celestial Laser)
-N/A / 150 (220) (Grand Laser)
Defence: 30

[Attack range 1 is for 'normal', while attack range 2 is for 'empowered']
[*Will only use the 'empowered' damage if both Solar and Luna are empowered]

Attacks:
Luna and Solar will spend most of their time near the player, usually Luna to their left and Solar to their right, levitating after them. If the player gets too far away they will teleport near to them as well, keeping with this pattern.
Most of the time their attacks will align, with some of them being 'combo' attacks involving both of them attacking in unison to create a stronger attack. Their general attack pool looks like this:
-The 'normal' one will launch an arc of 5 of their respective projectile type, while the 'empowered' one releases up to 12 projectiles in a 'burst' outward in all directions. If both are empowered both create bursts.
-They may both create up to 3 (4) constructs each. These are spherical entities that simply pursue the player, acting more as shields for the mages than actual threats.
-They may both create projectiles near themselves in preparation for another attack, but do not immediately launch them at the player. Instead they will both throw these projectiles at each other, creating large crystalised fireballs called 'fusion bolts' that chase the player before exploding. If Solar is empowered they move faster and if Luna is empowered they explode more violently when they expire, also if both are empowered it gains both these effects.
-They may both create lasers similar to the True EoCs'; thin, sweeping deathdays aimed generally in the player's direction. However, they will take it in turns to fire these, giving the player an easier time dodging.
-Finally, if both are empowered, they can create a 'Grand Laser' where one teleports next to the other and they both prepare their deathray attacks. The result is a colossal, sweeping deathray with insane damage, otherwise acting like the celestial laser attack.

Defeat:
Defeating either Solar or Luna will not cause them to be truly 'defeated', though it will stop them performing certain attacks like the projectile and construct summons, as well as their own celestial lasers, but they can still help the other mage with things like fusion bolts and the grand laser.
Defeating both will cause them to both explode into clusters of their respective particles before these clusters fly away, ending the fight.
Drops are dropped as soon as the second mage is defeated, with the cluster animation being solely cosmetic.

Drops:
Both have their own themed drops, with Luna having a bow, a spear, and a tome while Solar has a sword, gun, and summoning staff that makes their constructs. If the player defeats both of them in their empowered states they also drop another summoning accessory that summons 'chibi' Solar and Luna to protect the player that can be combined with the Celestial Stone if the player has one. In Expert Mode it drops an accessory that provides health regen and speed buffs in the day and damage and defence buffs at night.
In Master Mode, they have two different pet drops; Small Luna as a regular pet and Small Solar as a light pet.

Lore:
Two mages thought to represent the sun and the moon. It is believed that, under special conditions, the two can fuse into a powerful celestial entity.

Hints:
-Having a RoD for teleportation can prove very helpful, especially against both of their deathray attacks.
-Piercing and AoE weapons are good for dealing with their constructs, which is itself recommended as they otherwise risk making dodging harder for other attacks if in unfavourable positions.
-Focusing on whichever one is empowered will make dealing with the other one significantly easier

Extra Info:
-These two bosses were based on some of my first spriting attempts. However, outside of theming, they have no other similarities to the original Solar and Luna.
--Additionally, they were once tied with Boss Ideas 4's 'Eclipser', though these ties have also been cut
-Originally Luna was called 'Lunar', though this name was originally used for a different boss and thus it was changed.
[Added: 27/5/20]

09 - Centurion

Appearance: A somewhat humanoid creature made mostly of plant mass. The collar and helmet have been merged with its body so it can retain some shape. Its right arm and torso seem human, but the legs are little more than hanging tendrils and the other arm is a twitching mass of vines also.

Summon: Use the Earthly Beacon in the jungle. The boss can be taken anywhere once summoned without issue, though the item can only be used in the jungle. The boss will despawn if the player dies or gets too far away.

Fought: Post-Moon Lord
Specification: Post-Blacklight
Special: Returning boss
Progression: Later Bosses

Stats:
Health:
-675,000 (850,000) (1,083,750) (Centurion)
-2,500 (4,000) (5,100) (Writhing Orbitals)
Attack:
-285 (410) (Centurion Melee, Orbital Melee, Brute Melee)
-260 (367) (Centurion Energy Sphere, Orbital Nettles)
-270 (383) (Centurion Thorn Burst)
Defence:
-50 (Centurion)
-100 (Orbitals)*

[Orbitals, when hit with a projectile, will reduce its piercing capacity by 5 and will reduce any projectile with more than 10 max piercing down to just 10]

Attacks:
Phase 1:
The Centurion will spend most of the fight above the player, following their movements. Their attacks may disrupt this, but after attacking he will return to said position rapidly.
At the start, 10 Orbitals orbit the Sentinel in a tight ring. These Orbitals make piercing projectiles significantly weaker and can block non-piercing effects, meaning that the player has to break through this barricade to hit Centurion reliably.
Centurion has a few attacks it may use against the player:
-It may stop briefly before dashing at the player. The dash has varying ranges based on the Orbitals, but at the moment it travels a decent distance very quickly.
-Centurion may cause large, spiky thorns to erupt from the ground beneath it. If there is no nearby ground, it instead summons them in mid-air. They can also be summoned atop semi-solids.
-It may launch large energy spheres at the player. They are fast and can pass through blocks, and Centurion will launch numerous in succession (And in Expert Mode they gain a mild homing effect).
Defeating the Orbitals will cause them to launch out spikes in 8 directions.
Once down to 75% health, he enters Phase 2.
Phase 2:
-Another 20 Orbitals now orbit the Centurion, in a ring a little further out than the first. Any projectiles that get through the new outer ring can still be blocked by the remnants of the inner ring.
-Centurion's charges cover a lot more ground and are faster, though it the time between him stopping and charging is increased slightly (not in Expert).
-He gains a single new attack where he can launch an arc of 5 large energy spheres at the player. They move fast at first, but slowly decelerate before disappearing.
Once down to 50% health, he enters a 3rd phase.
Phase 3:
-Centurion summons 50 Orbitals in another orbiting ring, though this ring is significantly further out; encompassing both the Centurion and the player.
-Centurion's charge is slower now and covers less distance to accommodate for the movement limitation of the new ring
-Centurion has a new energy orb attack where he summons one, but it instead spirals outward from his position. Centurion stays still for a couple of seconds after launching the attack before returning to his regular position floating above the player.
Once down to 25%, he enters his final phase.
Phase 4:
-Centurion summons 20 Orbitals in a ring in the same position as the ones from Phase 1; causing overlaps so the player almost certainly has to break Orbitals to hit him reliably.
-His charge is now faster and covers more ground than even Phase 2's. (In Expert Mode it also creates energy orbs that linger in-place for a few seconds before despawning).
-The phase 3 'spiralling energy sphere' attack now has 4 (8) spheres instead of 1, each summoned in a cardinal direction (and the diagonals as well).
-His final new attack has him launch a barrage of energy orbs at the player. These accelerate over time.
-Occasionally, he will also try to heal himself. He will teleport somewhere nearby and accumulate power. If not damaged for a few seconds he will heal 5 (8)% of his health, but if attacked he returns to his regular position above the player and will immediately attack them. [Note: He cannot heal his Orbitals or summon any new ones, nor return to previous phases if he gets back over the 25% health threshold. Additionally, there is a 20-second cooldown before the heal can be attempted again if it's successful, and a 10-second cooldown if not.]

Defeat:
Explodes into gibs, apart from the head which flies away; green tendrils hanging from beneath the helmet.

Drops:
Always drops the Earthly Shard; a material for a later summoning item. Can also drop a sword or a magic tome. In Expert Mode it also drops an accessory that grants the player 2 Orbitals that orbit the player, damaging nearby foes and attacking them with spike projectiles.

Lore:
One of Scourge's Champions. Centurion's homeworld was fairly devoid of vegetation, so they tried to make a creature that could help plants grow better: Centurion was the result. However, it proved unstable and terrorised their planet. Eventually, when Scourge arrived, they were more than happy to let Centurion join his Champions.

Hints:
-In Phase 3, it's probably best to focus more on the new ring of Orbitals rather than Centurion until most of them are destroyed. This removes the mobility limit they impose, which is especially important for Centurion's final phase.
-Fast-firing, piercing weapons are best for Centurion, since the Orbitals will be blocking most of the player's attacks anyways, and piercing weapons may be able to still hit the Centurion even if they hit an Orbital.
--Additionally, in the final phase, it makes it easier to block Centurion's healing attempts.

Extra Info:
-Centurion was originally called Sentinel, but this was changed due to the name being identical to the Sentinels, seen prior, despite the two groups not being at all related.
[Added: 30/5/20]

10 - Cyclonus

Appearance: A long, thin mechanised worm. Its body is plated in a metal with a blueish hue with violet-coloured plates running down the middle in groups of 3. It has a single small spike on the end of its tail, and its front segment has a set of dark grey mandibles with violet teeth running down the insides. It also has a single violet-coloured sphere for an eye.

Summon: Use the Violet Beacon at the surface or in space. The boss can be taken anywhere once spawned without issue, and will even chase the player across the map if they try to flee, so the only ways to despawn the boss are to die or leave the world.

Fought: Post-Moon Lord
Specification: Post-Blacklight
Special: Returning boss
Progression: Later Bosses


Stats:
Health: 885,000 (1,150,000) (1,466,250)

Attack:
-320 (440) (Melee)
-260 (367) (Laser, Drone Laser, Drone Melee)
Defence: 85

Attack:
-290 (416) (Melee)
-260 (367) (Laser)
Defence: 112

Attack:
-300 (428) (Melee)
-260 (367) (Laser)
-290 (416) (Lightning Orb, Tornado)
Defence: 150

[All of Cyclonus' segments take 20% less damage from piercing projectiles. Additionally, any piercing projectiles that hit them will lose 50 (66)% damage against the next target, stacking multiplicatively per segment hit.]

Attacks:
Phase 1:
In Phase 1 Cyclonus' attack pattern is very simple. He will try to ram the player, like a Wyvern though moves significantly faster. Additionally, he will fire a single laser from his head roughly every second at the player (1.5-0.5 seconds based on how close he is to entering Phase 2).
At 80% health Cyclonus will enter his 2nd phase.
Phase 2:
Cyclonus will now act more like a Crawltipede; hovering around above the player and only attempting to melee them if they are too high off the ground. Cyclonus' attack pool becomes more fleshed out:
-He may fire a barrage of lasers from all his segments towards the player inaccurately. These barrages usually only last around 2-4 seconds.
-He may launch a Lightning Orb from his tail. This orb chases the player at high speeds, but otherwise acts like the Cultist's Orb: firing large thick bolts of lightning towards the player.
-He may summon a small ball of spiralling winds from his tail that moves towards the player horizontally while descending. Once it hits a block, semisolid or otherwise, it swiftly erupts into a large tornado, somewhat like Fishron's but silver and without the Sharkrons.
Once down to 50 (55)% health he will enter Phase 3.
Phase 3:
Cyclonus will now begin to follow the player at reasonable speed, a little slower than a Wyvern, but speeds up as his health wanes (Moreso in Expert).
Cyclonus will dispatch 4 (5) drones that orbit his head. The drones cannot be damaged, but still deal melee damage.
Cyclonus loses the laser barrage attack, though gains a single new attack in its place:
-The drones orbiting Cyclonus' head (and the head itself) fire a laser barrage at the player for a few seconds. It is far more accurate than Phase 2's barrage, and lasts for up to 5 seconds.
Once down to 25 (32)% health Cyclonus will enter his final phase.
Phase 4:
A storm will pick up, darkening the screen throughout the remainder of the fight. Cyclonus will become partly transparent, hidden by the storm, but his violet plates are illuminated, so the player can still see his movements.
He now alternates between chasing the player and flying overhead, changing every 5-10 seconds.
He gains a few new attacks and abilities in this phase:
-He may teleport; with his whole body disappearing before it re-appears elsewhere, starting with the head. Segments spawn as he moves after teleporting as opposed to them all spawning clumped together, so the player cannot abuse piercing weapons.
--Additionally, after a teleport, he may charge at the player at high speeds. He can only move in a straight line during the charge, though is incredibly fast. He may either continue his regular attacks or teleport again after a charge.

Defeat:
His body segments all explode, with the only remaining part being the spherical eye piece from the head. The eye piece quickly darts upwards and away and the sky clears, ending the fight. He drops his items as soon as he is defeated.

Drops:
Always drops the Violet Shard; a material used for a later boss summon, as well as either a summoner staff that summons orbiting drones to assist the player or a gun. In Expert Mode it additionally drops an accessory that allows all of the player's projectiles to inflict a defence-lowering debuff.

Lore:
One of Scourge's Champions. A battle-hardened cosmic worm made to battle in a gladiatorial pit for many years before Scourge's arrival. Not long after Cyclonus had been taken in as one of the Champions, his old homeworld was attacked and entirely destroyed; leaving Cyclonus wholly loyal to Scourge.

Hints:
-Attempting to change direction in this fight is actually rather problematic, as the lightning orbs and tornadoes linger and can block platforms. This becomes especially problematic in its 2nd phase, as Cyclonus himself acts like a Crawltipede then.
-Trying to outrun Cyclonus, even using the Pirate Ship Mount, is not possible in the 2nd phase as he is capable of accelerating up to 150mph in little more than a second, so stay close to the ground or have rows of platforms close to each other for easier dodging.
-While the visible parts of Cyclonus are smaller in Phase 4, his hitboxes remain the same. Try to keep a distance regardless of what his lights suggest.

Extra Info:
-As mentioned in his original info section, Cyclonus' name is based off of a Transformer of the same name. The same goes for his use of violet colouration.
-Cyclonus is actually just the orb; the worm body is just a mechanical construct.
[Added: 6/6/20]

11 - Wisp

Appearance: A humanoid fire elemental made of Ultrabright flames. Despite her large eyes and scrawny flame making her seem innocent enough, she's still one of Scourge's Champions and thus a force to be reckoned with.

Summon: Use the Luminous Beacon at night. The boss can be fought in the day without any issue, though the summon itself can only be used at night. The boss will despawn if the player dies or gets too far away.

Fought: Post-Moon Lord
Specification: Post-Blacklight
Special: Returning boss
Progression: Later Bosses

Stats:
Health:
-500,000 (635,000) (809,625) (Wisp)
-100,000 (165,000) (210,375) (Ultrabright Shield)
Attack:
-270 (383) (Wisp Melee, Shield Melee)
-290 (417) (Shield Explosion, Flame Javelin)
-265 (378) (Fireballs)
-300 (430) (Overheat Charges, Overheat Eruption)
Defence:
-35 (Wisp)
-70 (Shield)

Attacks:
Phase 1:
Wisp will summon a shield at the beginning of this phase, though cannot regenerate them mid-phase. She will usually follow the player while remaining a few blocks away from them, diagonally above them, usually trying to keep up with the player. Her attacks are as follows:
-She may launch 16 fireballs outwards in all directions. The first volley of 8 are in the cardinal directions and an 'x', with the second volley angled as to be in between the gaps of the first.
-She may launch 7 fireballs at the player in an arc. The fireballs further from the centre are slower, so the arc quickly becomes more of a 'v'-shape
-She may throw a fireball upward, which disappears. Shortly after, fireballs will begin to rain down from the sky, with thin blue lines indicating their trajectories.
Destroying the shield will cause it to explode, dealing heavy damage to the player if they are too close.
Once down to 75% health she will enter her 2nd phase.
Phase 2:
Wisp can now regenerate shields in this phase, after a delay of around 20 seconds. She has all of her previous attacks, though gains new ones as well.
-She may create a ring of fireballs around herself and launch them at the player. These, unlike previous ones, have a mild homing effect.
-She may create a spear of fire and throw it at the player. The spear is very fast, explodes upon hitting a solid surface, and creates fireballs as it travels that accelerate towards the player's last-known location.
Once down to 55 (60)% health she will enter her 3rd phase.
Phase 3:
Wisp will no longer try to keep up with the player, teleporting to new locations before every attack. Her shield now regenerates every 17 (15) seconds now instead of 20. She gains new attacks and upgrades some old ones:
-She can now charge at the player. It is a single long-ranged fast-moving charge from wherever she was at the beginning of the charge. (Additionally, she creates fireballs similar to the flame javelin's as she moves). She teleports at the end of the charge.
-Her attacks from Phase 1 are enhanced, with all projectiles beginning to accelerate after a short time:
--There is now a 3rd burst of fireballs in the 'burst' attack, in the same directions as the first.
--The 'arc' attack's projectiles are now pseudo-homing, like with the fireball ring.
--More fireballs are summoned during the 'rain' attack, and more of them fall over a larger area.
Once down to 40% health she enters her 4th and final phase.
Phase 4:
She regenerates a shield at the beginning of this phase, but loses the ability to regenerate them mid-phase; as she was in Phase 1. She launches attacks faster now (and even faster in Expert) and there is less time in-between attacks.
-She gains one final new attack in this phase: She surrounds herself with flames and charges at the player. She then teleports and charges again, eventually charging up to 4 times. Finally, she will teleport near the player and, after a short time, releases a powerful fiery explosion. She cannot move for 3 (2) seconds after the attack, however.

Defeat:
Releases a small burst of light before becoming less bright herself. Eventually teleports away, dropping her loot.

Drops:
Always drops the Luminous Shard; a material for a later boss summon. Can also drop a bow that rains down fireballs in a manner akin to the Daedalus Stormbow, also converting some arrow types into fireballs, or a magic staff that can rapidly launch homing fireballs at foes. Also drops an accessory in Expert Mode that grants the player mild damage reduction, allows all their projectiles to inflict On Fire!, and reduces damage taken from ignited enemies.

Lore:
One of Scourge's Champions. Her homeworld was pacifistic in nature, so Scourge had little trouble taking over. As he could not find a strongest fighter, he found the one he considered to have the strongest fighting spirit, and raised her alongside the other Champions.

Hints:
-As this boss is projectile-heavy, teleports and dashes become very helpful here
-Do not attempt to just run in one direction. Many of her projectiles are homing or accelerate enough to catch the player, and her dash attacks are fast and cover lots of ground.
-Once her shields are down, you'll likely want to deal as much damage as possible before they regenerate if it's Phase 2 or 3. However, don't get greedy or you might end up taking damage.

Extra Info:
-Wisp, as with the other Champions, are returning bosses from a previous guide given overhauls to their fights and appearances. Originally, Wisp had a rocky throne similar to the Brimstone Elemental's Brimrose, but admittedly this was because I couldn't sprite legs.
-The fact the lore talks about raising her alongside the other Champions, this means she could theoretically be the youngest of them.
[Added: 11/6/20]

12 - Dystopius

Appearance: A shadowy wraith in a large, ragged cloak. Chains are draped over his body, some with blades on the ends. His face is hooded over and obscured, though 4 eyes peer through on its right side. A large, red crystal rotates within, visible through a hole in the cloak.

Summon: Use the Malignant Beacon either at night or in the cavern layer. Unlike the previous 3 Champions, Dystopius will actually enrage if not meeting its conditions, increasing its damage output. Alternatively, summoning it during a Solar Eclipse will buff all its damage and defence, though rewards the player an extra drop.
The Beacon requires the player to defeat 2 other Champions before it can be used, as well as at least 5 Chained Wraiths; powerful enemies that spawn in the underworld.

Fought: Post-Moon Lord
Specification: Post-Champions*
Special: Returning Boss
Progression: Yes, Later Bosses

Stats:
Health: 675,000 (1,000,000) (1,275,000)
Attack:
-300 (430) (Melee)
-290 (416) (Chain, Shadow Sphere)
-280 (400) (Phantom Chain)
-400 (600) (Execution)
Defence: 75

Attacks:
Phase 1:
Dystopius will spend most of this phase either floating slowly towards the player or teleporting. It uses attacks seemingly-randomly, though will not attack whilst teleporting. Its attacks are as follows:
-May throw 5 chain knife projectiles in an arc towards the player. Both the knives and the chains deal damage, though the chain is not very long, only around 5 (6) blocks.
-May launch a series of shadowy spheres at the player. These have a homing effect, though the effect weakens as they travel
-May charge at the player. However, two shadowy silhouettes will also follow him at slightly different positions, which both also deal his contact damage. After the charge these two silhouettes disappear.
Once down to 80 (85)% health he will transition to his 2nd phase.
Phase 2:
Dystopius no longer floats towards the player, and only moves via teleportation outside of the infrequent dash attacks. He will teleport three times, attacking every third teleport.
The first 2 teleports will create shadowy silhouettes where he was, though these disappear after he attacks.
-His charge attack is slightly different, with no silhouettes being spawned near Dystopius, but instead both he and his previously-spawned silhouettes all charge at the player at the same time. The silhouettes disappear at the end of the charge, and Dystopius himself will teleport afterwards.
-He may throw a single chain knife at the player, which disappears after a short time. It will then re-appear near the player from a small portal, aimed at the player again, and will disappear again after a short time. It re-appears up to 4 times in total before truly despawning.
-He may throw an arc of 4 chain knife projectiles at the player. These disappear after a couple of seconds, only to re-appear near the player from the cardinal directions, aimed at the player again.
-He may charge at the player, then turns around to launch a volley of shadow spheres at the player. These have a mild homing effect.
Once down to 60% health he transitions to phase 3.
Phase 3:
The background will darken, and he will go back to following the player again as in Phase 1. While his melee and shadow sphere hitboxes remain the same, the chains now have an unusual property. All chain projectiles are much faster, but they no longer deal damage. Instead, a silhouette of the chain knives, called a 'phantom chain', will follow all chain knives with a mild delay and deal damage instead, leaving a mildly disorienting effect.
If the player gets too far from Dystopius a volley of regular and phantom chains will begin to bombard the player. The regular chains deal no damage still and are inaccurate, more for visual effect, while the phantom chains are will be launched in pairs to trap the player between them.
All previous attacks using chain knives now follow the phantom chain properties.
Once down to 45% health he transitions into his 4th phase.
Phase 4:
All Phase 3 effects still apply, though he will now gain new attacks
-Chain knives with long chains will fall from the sky randomly near the player. The phantom chains mean that these can trap the player until they despawn. However, Dystopius is immobile during the attack.
-Dystopius may disappear, and then re-appear next to the player in a 'ready' stance. After a short delay he will laugh and swing a larger variant of the chain knife at the player, complete with a large red 'slash' in front of him. This attack deals significant damage on hit, and can be used up to 2 (3) times in succession.
[Expert Mode exclusive Phase]
If down to 15% health in Expert Mode, he will transition to a final, 5th phase
Phase 5:
The screen darkens until it's almost entirely black, and Dystopius will laugh.
He will only ever attempt the 'Execution' attack in this phase, ditching all previous attacks.
As his health lowers, he will become less and less visible, until eventually only his eyes and the 'slash' effect left behind by his attacks are visible.
This continues until the fight ends.

Defeat:
Will hunch over before exploding into a mixture of cloth and shadowy remnant. The darkness effect from his last few phases will lift and he will drop his loot.

Drops:
Will always drop a Malignant Frame; the likely-final piece needed for the fragments. Also drops a chain knife-like weapon that acts similar to the Solar Eruption, and a summoner whip that is also similarly a chain knife. In Expert Mode it also drops the Ominous Shroud, which grants a dodge chance that gradually increases with health lost, though inflicts a debuff on every successful dodge.

Lore:
Presumed Scourge's oldest and strongest Champion. His origins are so old that Scourge has no documentation of his origins; neither biological nor homeworld, so he is simply classed an anomaly.

Hints:
-Don't try to run too far from Dystopius, as the chain knives it spawns are very fast and spawn dangerously close to the player.
-When he attempts the 'Execution' attack, move diagonally away from him. The slashes have a deceptive amount of verticality, which may catch players attempting to simply free-fall outside of the attack's range.
--Additionally, make sure you use an open arena, especially in Expert Mode, where his final phase is a constant flurry of said attack in succession. It also helps with giving more room to dodge the shadow spheres.
-The weird effect from Phase 3 onwards with its chain knife projectiles may take getting used to, though luckily the Wraiths that need to be fought prior can show off this effect. In battle, however, also keep an eye on his health so you know when he goes to change into Phase 3, and on his movements as he will go back to chasing the player again in Phase 3 also.

Extra Info:
-Dystopius, as with the other 3 returning Champions, was one of the original 4. However, in his debut, he was no more special than the other three and wasn't considered stronger than them.
-While 'Powerful cloaked figure serves cosmic threat' sounds similar, the boss wasn't intended to be based off of Signus. That was an accident.
[Added: 13/6/20]

13 - Dragon Fly

Appearance: A large insect with design elements taken from numerous sources. Its arms are mantis-like scythes, its tail scorpion-esque, and body akin to a caterpillar. In fact, outside of the name, it shares little in common with an actual Dragonfly.

Summon: Can be summoned either by using a Juicy Grub in the jungle; a rare critter that spawns in the underground jungle, or anywhere by simply killing 20 Dragonflies. The boss can be taken anywhere once spawned, but will move faster outside of the jungle.

Fought: Pre-Hardmode
Specification: Whenever
Special: No
Progression: No

Stats:
Health:
-4,000 (6,750) (8,606) (Dragon Fly)
-10 (20) (30) / (150) (225) (Swarmers)
Attack:
-30 (48) (Dragon Fly Melee)
-12 (20) / (60) (Swarmer Melee)
-18 (35) (Dragon Fly Acid Spit)
Defence:
-5 (Dragon Fly)
-2 (Swarmers)

[Swarmers receive health and damage buffs in Hardmode, like regular enemies would.]

Attacks:
The Dragon Fly will spend a lot of the fight chasing the player at a moderate pace. However, it does have a few attacks it may use to keep things interesting.
-It may hover backwards, line up with the player, and perform a relatively fast horizontal dash
-It may stop for a moment before charging at the player. However, unlike its other charge attack, this one predicts the player's movements and instead charges to where it predicts the player will be.
-It may create a 'screeching' noise, summoning several Swarmers from off-screen to distract the player
-It may fly near the player and spit blobs of acidic spit at the player. These blobs are affected by gravity and are destroyed on contact with solid blocks.

Defeat:
Explodes into gibs. The Swarmers don't die with the boss, however.

Drops:
A Mantis Strike; a strong pre-hardmode whip, and a throwing spear called the 'Dragonfly'. Also drops a summoning staff that summons dragonfly minions to rush down and swarm foes. In Expert Mode it can drop a Tail Stinger which increases damage dealt by minions and bees and allows them all to inflict Poisoned. If killed in Hardmode it drops Mantis Wings as well; a weak pair of early-Hardmode wings.

Lore:
A large and powerful lone hunter, though seems attached to the smaller Dragonflies that inhabit lakes. Large grubs are a delicacy for it, and it will take extreme measures to obtain them. Likely not the last giant bug you'll be seeing, sadly.

Hints:
-Hermes Boots will allow you to keep away from it as it chases you while in a non-enraged state, so consider grabbing some before facing it
--It is as fast as Hermes Boots when enraged, so Lightning Boots may be better. Additionally, they provide flight, which can make dodging its charges easier.
-Grenades can kill the Swarmers exceptionally easily in Pre-Hardmode, or in Normal Mode in-general
-It may be worth fighting it again in Hardmode for some easy-access early-game wings. Bear in mind, however, that the Swarmers receive stat buffs in Expert.

Extra Info:
-The boss was designed long before Terraria's implementation of Dragonflies, and sprite-wise also predates all other sprites made on this page. However, the summon method was altered to incorporate them.
--However, in terms of design, it is predated by Scourge's Champions, Mia, Revenant, and, by technicality, the Bumbleknight also.
-Its lore's final sentence, talking about other giant bugs, may be referring to Queen Bee, or perhaps just other generic large bugs that inhabit the underground jungle
--Though, in terms of stats, it may be better to face Queen Bee first, so while it may refer to QB it's not certain.
[Added: 13/6/20]

14 - Fairy King's Behemoth

Appearance: A colossal, vaguely draconic creature. Its body is large and pink with a grey underside and two short and rather stubby legs, and a pair of unusually small wings on top. Three 'heads' seem to protrude from within its mouth. It seems to have part of a skeleton placed on its back, with the skull obscuring its eyes.

Summon: Use the Fairy King's Sceptre in the Hallow. The Behemoth will jump down, roar, and begin the fight. Taking the Behemoth out of the Hallow isn't an issue, nor is the time you fight it. The player will be inflicted with Heavy Gravity at the start of the fight, which persists until stated otherwise.

Fought: Post-Moon Lord
Specification: Post-Blacklight
Special: Progression point
Progression: Yes

Stats:
Health:
-1,200,000 (1,865,000) (2,377,875) (Behemoth)
-850 (1,300) (1,658) (Hallow Locust)
-168,000 (340,000) (433,500) (Hydra Heads)
Attack:
-475 (730) (Behemoth Melee)
-400 (600) (Hydra Head Melee)
-350 (534) (Locust Melee, Hallow Breath*, Hydra Flamethrower*, Hydra Flame Spit*)
-370 (560) (Hallow Sludge*, Shockwave, Hallow Spikes*, Hallow Crystals*)
Defence:
-105 (Behemoth)
-10 (Locust)
-120 (Hydra Heads)

[All attacks marked with an asterisk will inflict Energy Surge in Normal Mode - 33% chance]
[In Expert Mode all attacks have a chance to inflict Energy Surge - 50% chance]

Attacks:
Phase 1:
The Behemoth forces the player to remain close to the ground, while also being grounded itself. Most of its attacks are slow, but deal high damage.
-It may spew a large cloud of energy called 'Hallow Breath'. The cloud produced slowly moves towards the player, and is almost as large as the Behemoth itself.
-It may leap towards the player, with a reasonably slow wind-up. At the end of the leap it still has momentum and thus slides for a short distance based on horizontal movement during the jump. (In Expert it also creates a large shockwave similar to the Ogre's.) The attack becomes more common the further the player is from the Behemoth.
-The Behemoth may spew out a large swarm of Locust-like bugs from its mouth. These simply chase the player and, at this point in progression, are fairly weak. However, their weakness is made up for by number, and the fact that the Behemoth itself will quickly switch to its next attack.
-The Behemoth may jump directly upward, landing to create a reasonably large shockwave. This only happens if the player is very close to it.
-The Behemoth may vomit a large cluster of Hallow Sludge projectiles from its mouth. These are affected by gravity, and each globule has a different trajectory.
-The Behemoth's 3 hydra-like heads can all begin to spit pink, fireball-like projectiles at the player. There are 2 variants of this attack, though both last as long.
--Variant A has them bounce like the fireballs produced by the Flower of Fire's
--Variant B's has them move in a straight line at considerable speed.
-The Behemoth may slam a single foot down, causing numerous large spikes to erupt from the ground randomly nearby.
If the player ever gets too far from the Behemoth, pink particles will begin to spawn around them. Around a second later, they will be forcefully teleported very close to the Behemoth, and inflicted with the Chaos State debuff for 5 (10) seconds.
Once taken down to 50% health, the Behemoth will switch to Phase 2:
Phase 2:
The Behemoth becomes airborne, and the Heavy Gravity debuff is lifted from the player.
In this phase, the Behemoth can fly almost as fast as the player moves both horizontally and vertically, and will generally try to stay Horizontal to them.
The 'vertical leap', 'hydra fireball variant A', and 'hallow spike' attacks are dropped. The 'hallow sludge' globules travel further, the 'hallow breath' cloud moves faster, and the 'horizontal leap' attack now has the Behemoth summon a temporary platform under itself to jump from, and gains more distance from a jump. All other attacks remain the same.
-It gains a new attack where it summons large crystals randomly overhead that fall down after a short time. They pass through solid blocks until at or beneath the player's height, where they can now get stuck in blocks.
-It can also now charge at the player. It will lean forward slight before charging at them, with the charge having limited vertical movement but high horizontal speed
-It gains one last attack where it flies over the player's head and attempt to land on top of them. This attack ends either with him falling too low, where he begins flying again, or hits a solid block, creating a shockwave.
Once down to 15 (10)% health, it enters its 3rd phase.
Phase 3:
The Behemoth itself becomes invulnerable, and the three hydra-like heads poking out of its mouth burst out; becoming three separate worm entities.
The Hydra Head worms can fly, and have two different attack types; a brief charge where they gain additional movement speed in exchange for losing turning control, and a short-ranged flamethrower from their head segments.
The Behemoth can only use three attacks in this state; the 'hallow sludge', 'hallow crystal' and 'hallow breath' attacks, and attacks less often. He follows the player, still, but is slower than before. The teleport effect is still in-place, however, so the player still cannot stray too far from it.
Killing a worm will cause it to return to the Behemoth's body, only to be eaten. It regains 15 (20)% health per worm, and killing all 3 [and thus returning 45 (60)% health] will make it transition to its final phase.
Phase 4:
The Behemoth becomes grounded again, and re-applies Heavy Gravity to the player.
The Behemoth gains back most of its attacks, though 'hallow spike' and 'vertical leap' do not return as stronger variants are implemented in their place.
Additionally, both 'hydra fireball' variants are simply launched from the Behemoth's mouth, as the Hydras are gone.

Defeat:
Collapses to the ground with a defeated roar. Begins to glow before letting out a powerful flash (Like the OOA crystal). Once the player can see again, the Behemoth will be gone and in its place will be its loot.
Additionally, a message saying 'The Hallow becomes more radiant' will be displayed, and Hallow enemies will become stronger, and new enemies will begin spawning.

Drops:
A sword that launches hallowed fireballs, a throwing spear that releases damaging fairy dust, a flail that launches its ball once swung, a crystal-launching magic tome, a bow that rains crystal shards from the sky, a gun that makes all bullets a stronger variant of the crystal bullet, and a magic staff shaped like one of the hydra heads that launches hallowed sludge. Can also drop a summoning staff that summons a mini-Behemoth, with 1 hydra head, and additional summons increase the amount of heads; all heads shooting hallowed fireballs at enemies. Will always drop Unbreakable Scales and some Radiant Shards, as well. In Expert Mode it drops Behemoth Wings; plain but powerful wings, as well as a shield that grants immunity to a lot of debuffs and grants a dash that can be combined with the Ankh Shield. Can drop an upgrade to the Rod of Discord after its first defeat with a 25 (40)% chance, which creates a damaging explosion around the player and 0.3 seconds of immunity after a teleport, at the cost of the Chaos State's damaging teleport taking 50% health instead.

14 - Fairy King's Behemoth (Continued)

Lore:
Former pet of a fabled fae king, believed to have consumed him once it grew to its adult size. It rampaged endlessly around the Hallow until it was sealed away alongside the ancient spirits of light and dark.

Hints:
-Wings are still somewhat useful in both the early and late phases as they still provide the player some amount of verticality, allowing for easier dodging for certain attacks
-Be careful to not stray too far from the Behemoth. This can make its dangerous 'horizontal leap' more common, or force the player to be teleported near it while also debuffing them with Chaos State.
-Piercing weapons can make quick work of both the Locusts and the Hydra worms in Phase 3, as neither have any sort of resistance against piercing weapons.
-The Locusts are more of a distraction than anything, acting as a 'meat shield' for the Behemoth. However, it's still recommended to deal with them as their damage is still quite high and they're fast enough to be generally quite annoying.

Extra Info:
-The Behemoth's sprites took around 3-4 days straight to make which is arguably the longest time taken for an individual sprite.
-Originally, the Behemoth wasn't planned to be a Hallow boss, as its main colour had not been decided. Once 'Pink' was decided by vote, its lore was crafted, and the Fairy King's Behemoth was born.
-Phanta, like with the Sentinel and Sharlteron, has made the Behemoth a theme: https://soundcloud.com/phantasmental/behemoth
https://youtu.be/NosUu4HZRWc
[Added: 13/6/20]

15 - Cosmic Dragon

Appearance: A fairly large, orange-y dragon. It has crystal-like growths on and near its wings, as well as its shoulders. A small flame burns on its tail. It has two horns on its head and a single thin eye. Its wings leave a space-y trail as they move.

Summon: Use the Comet Shard at night, made using meteor bars, ectoplasm, and some souls of light and night. The boss can be taken into daytime, though will enrage; gaining increased damage by around 1.3x (1.5x). While it can be fought after Plantera, it is similar to EoL; where you may want to wait a little longer due to its stats.

Fought: Hardmode
Specification: Post-Plantera
Special: No
Progression: Later Bosses

Stats:
Health: 65,000 (90,000) (114,750)
Attack:
-85 (150) (Melee)
-75 (136) (Meteor Shower, Cosmic Fireball)
-72 (131) (Cosmic Slash, Starfall)
-65 (123) (Fireball Trail, Slash Sparks)
Defence: 20

Attacks:
Phase 1:
The Cosmic Dragon will usually follow a cycle of charging at the player 3 times, then attacking. Each charge covers a lot of ground, with each subsequent charge per cycle covering a little more. His attacks are as follows:
-May spew cosmic fireballs from his mouth for up to 2 seconds. These fireballs accelerate gradually and explode violently on contact with blocks. They also leave a damaging trail for a very short time as they move.
-It may roar, fly in a loop, and summon numerous small meteorites to rain down from the sky. They fall, evenly spaced, either left to right or right to left, as opposed to randomly.
-It may flap its wings, summoning three crescent-shaped 'cosmic slash' projectiles. These pass through blocks for a couple of seconds before they lose this ability in favour of ricocheting off of blocks instead.
-It may roar, summoning numerous star-like projectiles randomly near itself, before they are all suddenly launched towards the player at high speeds. They pass through blocks but despawn eventually.
Once down to 40 (60)% health, the Cosmic Dragon will switch to its 2nd phase, signalled by a loud roar.
Phase 2:
The Cosmic Dragon will now charge 4 times in succession before using one of its main attacks.
While it gains no new attacks in this phase, all of its previous attacks have been changed.
-The cosmic fireballs now have a mild homing effect and will thus curve slightly in the direction of the player.
-The meteor attack now has a 2nd string of meteorites that fall in the opposite direction once the initial volley ends.
-5 'cosmic slash' projectiles are spawned instead of 3 and they move notably faster
-The star projectiles' spawning area is far greater, and more of them are spawned. Additionally, they explode on contact with blocks or after travelling too far.
[Expert Mode exclusive Phase]
If down to 25% health in Expert Mode, it will enter an additional 3rd phase.
Phase 3:
It once again goes back to only 3 charges per cycle, but they are faster and the gap between the final charge and one of its projectile attacks is shorter, meaning less downtime.
Similar to Phase 2, the Dragon does not gain new attacks, but instead enhances its original roster even further.
-The fireballs' trails linger for significantly longer, and their homing abilities are enhanced a little further
-The meteor attack has a 3rd volley dropped in the middle of the previous two
-The slashes are faster and, on contact with blocks at either behaviour type will spawn lingering sparks
-The stars can now be summoned in an immensely large radius, and a 2nd volley is spawned after the first

Defeat:
Explodes into gibs, dropping its loot

Drops:
Will always drop Cosmic Dragon Scales; used for making some armour and a couple of weapon upgrades. Also drops a bow, sword, and a tome. In Expert Mode it drops a set of decently-powerful wings, around the same tier as Fishron's, though without any specific extra benefits; just good wings.

Lore:
A large, space-dwelling dragon. It feasts on meteorites and on creatures that dwell too close to its home in the skies, though the glistening spectacle of a comet seems to draw its attention above all else.

Hints:
-Dashes prove exceptionally useful for this fight. It makes dodging the meteors easier, especially in the second phase, and allows you to distance yourself more easily from its other projectile attacks
-Having equipment from Golem or the Pumpkin/Frost Moons is recommended due to the amount of health the player has to get through in total; around double Plantera's.

Extra Info:
-There are three tiers of planned Cosmic Dragon, with this one originally planned to be a juvenile. However, to make things less hectic, this was made their standard 'adult' form, with the previously-planned adult being made into an Elder.
-The Cosmic Dragons were also originally made for Reality, but were also scrapped. This was, fittingly, the first one made.
[Added: 13/6/20]

16 - Elder Cosmic Dragon

Appearance: A larger, more powerful version of the Cosmic Dragon. Its back is coated in spines, and more crystal-like growths are present on its knees. Its hands are also now coated in them as well, as opposed to just its claws.

Summon: Use the Grand Comet Chunk at night. Like with its smaller form, it can be taken into the day, but its damage output is enhanced by 1.4x (1.65x). The materials for the summoner include meteor bars, luminite, and some of the materials dropped by the smaller Cosmic Dragon.

Fought: Post-Moon Lord
Specification: Post-Moon Lord
Special: No
Progression: Later Boss

Stats:
Health: 140,000 (232,000) (295,800)
Attack:
-175 (288) (Melee)
-160 (270) (Shooting Stars, Cosmic Flames)
-170 (282) (Meteor Shower) (Inflicts On Fire! - 25 (33)%)
-200 (332) (Nova Wave) (Inflicts Energy Surge - 50 (100)%)
Defence:
-20 (Phase 1)
-40 (Phase 2)
-60 (Phase 3 (And 4))

Attacks:
Phase 1:
Like the smaller Cosmic Dragon, it will charge at the player 3 times, but ends with an additional 4th charge horizontally towards the player, flying to be level with the player beforehand. It will then use one of the following attacks before repeating the cycle:
-Will fly towards the player for a few seconds, spewing large cosmic flames from its mouth.
-Will summon a burst of 12 evenly-spaced stars outwards in all directions. These accelerate as they move.
-It may roar, which summons a shower of meteors to fall from the sky for a few seconds. The places they fall from and their paths are shown via thin yellow 'beams' that phase to a red once a meteor begins falling there.
Upon being taken down to 60 (70)% health it will transition to its 2nd phase.
Phase 2:
It will now only charge 3 times, but the third charge will curve slightly towards the player. Most of its attacks are just upgrades, but it does gain a new one.
-The 'cosmic flame' attack now creates additional fireballs that are launched in random directions from the initial flame breath
-The 'shooting star' stars will slowly rotate as they travel, and a 2nd set of 4 more stars is released after the initial volley that rotate the opposite direction
-More meteors fall during the 'meteor shower' attack, and they all fall faster
-Its new attack has it charge up energy before releasing a powerful 'wave' of energy, made up of several energy orbs strung together. The trajectory of the attack is adjusted throughout, thus forcing the player to keep moving.
Once down to 25 (40)% health it transitions to Phase 3.
Phase 3:
Goes back to 4 charges, with the first 3 being regular charges and the 4th being the 'curving' charge from Phase 2. However, it also now breathes cosmic flames during the 4th charge, though without the fireballs.
-After the initial use of the 'cosmic flame' attack the Elder will swoop back around for a second use. Additionally, more fireballs are spawned in the second use.
-The stars rotate faster in the 'shooting star' attack, and the second volley now consists of 8 stars instead of just 4.
-More meteors fall during the 'meteor shower', and a few extra 'stragglers' fall after the attack would normally end.
-The 'nova wave' takes less time to charge, but is otherwise the same.
[Expert Mode exclusive Phase]
If down to 20% health in Expert Mode, it will enter an additional 4th phase.
Phase 4:
Charges faster, and the downtime between the final charge and one of the main attacks is reduced.
-The 'cosmic flame' attack once again goes back to a single charge, but at the end of it the dragon will launch several fireballs skyward that are affected by gravity and thus fall back down. Additionally, all fireballs become explosive.
-More stars are present in both volleys of the 'shooting star' attack; 16 in volley 1, and 10 in volley 2.
-The time taken between the yellow 'beams' appearing and the meteors actually falling is reduced. Additionally, more 'stragglers' will spawn afterwards and will continue to fall even when it continues charging for the next cycle.
-A 2nd Nova Wave is fired after the first, though this time the second isn't fired from where the player is, but instead fired towards a point based on their movement.

Defeat:
Lets out a roar of defeat and explodes into gibs

Drops:
All of its weapon drops are upgraded variants of the original's, and it will always drop Armoured Cosmic Scales that can be used for crafting. In Expert Mode it drops an Astral Feather; a material that can be used to upgrade the wings received from the original.

Lore:
A Cosmic Dragon that has lived for many years may achieve this form. Almost nothing poses a threat to it within its domain. It is the peak of a Cosmic Dragon's strength outside of more taboo means.

Hints:
-Teleports are always useful, though be careful when it comes to using dashes, as it has numerous attacks that involve numerous projectiles falling from varying angles
--However, dashing through the 'shooting star' attack is a reliable way to dodge it in later phases
-In Phase 2 and onwards, keep an eye on what attack it plans on using after the final charge. The Nova Wave is fast and deals high damage, as well as providing a highly-detrimental debuff.

Extra Info:
-The Elder's lore entry's final sentence is designed to hint at another Cosmic Dragon fight later in the game.
--Though in this layout it's fairly obvious, seeing as this is simply an info page and not a mod as of writing this
-With it being a larger and stronger version of the previous Cosmic Dragon, having similarities in fight make sense. However, none of the moves are directly taken from the previous fight, meaning outside of some visuals and patterns the boss is almost completely different.
[Added: 14/6/20]

17 - Twisted Cosmic Dragon

Appearance: A strange incarnation of the Cosmic Dragons. Its skin is a dark grey and appears to have decayed away around its chest, revealing unusually-bent ribs and a crystal-like growth near the chest. The place where Cosmic Dragons normally have an eye is now overgrown by another crystal, with 4 smaller slits around it acting as makeshift eyes in its place. Its wings are thinner, and the small 'cosmic' effect produced is now far more prevalent.

Summon: Use the Cosmic Flesh Clump at night. It can still be taken into the day, but it deals 1.6x (2x) damage. The materials for the summon include some of the drops from the previous 2 Cosmic Dragons, as well as some other Post-Blacklight materials.

Fought: Post-Moon Lord
Specification: Post-Blacklight
Special: No
Progression: No

Stats:
Health: 640,000 (800,000) (1,020,000)
Attack:
-220 (380) / 230 (400) / 240 (420) / (440) (Melee)
-205 (358) / 215 (378) / 225 (398) / (418) (Cosmic Flames, Shooting Star, Cosmic Fireball)
-210 (364) / 220 (384) / 230 (404) / (424) (Comet Shower, Astral Clump)
-N/A (N/A) / 240 (413) / 250 (433) / (453) (Starnado)
-N/A (N/A) / N/A (N/A) / 275 (470) / (490) (Supernova)
Defence: 100

[All of the Dragon's attacks can inflict Energy Surge - 33 (50)%]

Attacks:
Phase 1:
The Cosmic Dragon will charge at the player 3 times. The first two charges are normal, but the third will predict the player's path and charge where it expects the player to be. After these charges it will use one of its attacks before repeating the cycle:
-It may charge at the player again, spewing a long stream of cosmic flames from its mouth. Cosmic fireballs are spawned as it does this, being launched in random directions. These fireballs explode only after around 0.5 seconds, and thus don't linger.
-It may roar, summoning numerous stars near the player. After a short delay these will begin to accelerate towards where the player was when they began moving, though do not home-in.
-It may launch numerous fireballs from its mouth in random directions. These fan outward as they move and are unaffected by gravity or blocks.
-It may roar and launch small comet shards into the sky. After a few seconds they will begin to rain down again at incredible speed, though their paths are displayed prior by small thin blue lines. They explode on contact with blocks.
-It may roar, causing numerous meteor-like chunks to rise from below. Their spawning positions are random, and after a few seconds they will begin to decelerate and eventually stop mid-air, lingering in their positions for some time, acting as additional area-denial.
Once taken down to 60 (65)% health, it will enter its 2nd phase, signalled by a roar.
Phase 2:
The Cosmic Dragon will now charge 5 times, though charges faster. The final charge is a little slower than the others, but retains the 'prediction' element of Phase 1. It gains 1 new attack, and enhances all of its old ones:
-The charge during the 'cosmic flame' attack now slightly homes in on the player, and lasts a little longer before the flame stream subsides.
-Now, a total of 3 volleys of 'shooting stars' are summoned near the player, one after another, as opposed to the original single volley
-More fireballs are spawned during the 'cosmic fireball' attack, and they move faster
-More shards are dropped during the 'comet shower' attack, and their explosions are a little larger
-Far more meteor chunks are summoned during the 'astral clump' attack, and their spawning range is larger.
-Its new attack has it launch a single homing tornado-like projectile at the player. On contact, or after a few seconds of chasing the player, it explodes into a dark-blue tornado. Unlike Fishron's, this one is the same width throughout, but very tall. Shooting Star projectiles appear within it, being launched out randomly, until the 'starnado' despawns.
Once reduced to 30 (40)% health, it will roar again, this time regenerating back 10% health before transitioning to its next phase.
Phase 3:
Charges 4 times, though both the first and large charges use the 'prediction' element. Gains a single new attack, but enhances all the old attacks again:
-The 'cosmic flame' attack's flames now linger as they are released, though eventually extinguish themselves
-More stars are summoned in each 'shooting star' volley, and the third one is now twice as large as both the previous two
-The 'cosmic fireball' attack's fireballs now home-in slightly if the player is close to them
-More shards are dropped during the 'comet shower' attack, and a second wave will fall after the initial wave, though only consisting of half the comets of the first
-More meteor chunks are summoned during the 'astral clump' attack, they linger for longer before despawning, and they now explode instead of just disappearing
-Two tornado projectiles are spawned during the 'starnado' attack, with the other dropped directly beneath the Cosmic Dragon, so two Starnadoes are spawned. They also spawn more stars than before.
-Its new attack has it build up energy and release an immensely powerful explosion around itself. The explosion has a very large radius, and afterwards smaller explosions will happen nearby in random places, signalled by small cyan rings appearing to display the areas of these explosions.
[Expert Mode exclusive Phase]
If down to 10% health in Expert Mode, it will roar again and regenerate 20% health, and enter a 4th and final phase
Phase 4:
It charges 4 times, with all 4 charges using 'prediction' elements. All its previous attacks are enhanced for one final time:
-The 'cosmic flame' attack spawns more fireballs, and the lingering flame trail lasts longer
-The 'shooting star' attack spawns more stars, and an additional 4th wave is spawned after the third. Unlike the others, they are spawned in a predetermined ring.
-The 'cosmic fireball' attack's projectiles can target the player from a longer distance, and instead of fireballs being launched all at once they are spawned in a rapid-fire flurry. Far more fireballs are also spawned.
-The 'comet shower' attack's comets fall faster and take less time to fall. The second volley also contains roughly 2/3 of the comets the first volley had.
-The 'astral clump' attack spawns more meteor chunks, and the area they can spawn is greatly increased.
-The 'starnado' attack's Starnadoes spawn far more stars, and they are now aimed directly at the player as opposed to being launched randomly.
-The 'supernova' attack is generally faster, and more small explosions are spawned after the initial one.

Defeat:
Roars, then small explosions erupt from it before it explodes into gibs a few seconds later.

Drops:
Always drops Twisted Scales; a material that can be used to upgrade a large array of items, or to make new ones. Drops stronger versions of its original three items, as well as a star cannon variant, a bag of infinite fallen star ammo, or a summoning staff that summons a mini Cosmic Dragon. In Expert Mode it drops Astral Matter; used for the final upgrade of the original Cosmic Dragon's wings.

17 - Twisted Cosmic Dragon (Continued)

Lore:
Due to starvation, this cosmic beast has cannibalised its own kind. Its body, unable to handle the immense energies of its slain brethren, has been mutated in a beautiful, if brutal way.

Hints:
-Teleports and dashes prove very helpful, as usual. Dashes can throw off its 'prediction' charges, and help the player escape from shooting star clusters easier, while teleportation allows the player to more easily navigate past things like the meteor chunks and starnadoes.
-Having an enclosed arena is not recommended for this boss, both due to its fast movements as well as its many attacks that have area-denial effects, like the starnadoes.
--Continuous navigation of the player's world may be effective, as it means the player is less likely to be forced to double-back through starnadoes and other obstacles, but also allows the player to potentially distance themselves from falling comets or lingering meteor chunks and Starnadoes

Extra Info:
-The Twisted Cosmic Dragon is very much confirmed and emphasised as being an unnatural form of the Cosmic Dragons, both through it and the Elder Cosmic Dragon's lore, its naming, and general appearance.
--However, in terms of differences, it is very different from the previous Dragons, with a different posture, body structure, and even differences in things like its eyes and jaw.
-There is, with this form, now a Cosmic Dragon fight through three key stages in progression: Post-Plantera, Post-Moon Lord, and Post-Blacklight. (However, there is not one specifically for Post-Golem itself as the 'main' Cosmic Dragon is realistically intended to be fought Post-Golem anyways).
[Added: 16/6/20]

18 - Ebony Flame

Appearance: A strange, humanoid entity made of Cursed Flames. He wears a black hat and trenchcoat and carries a black and gold revolver-like gun in his right hand, usually concealed in his right pocket.

Summon: Use the Otherworldly Ember at night. Time is set to midnight throughout the fight, so there isn't a need to worry about running out of time. The Ember itself is a rare enemy drop once the Behemoth has been defeated, making the boss technically a secret one.

Fought: Post-Moon Lord
Specification: Post-Behemoth
Special: Secret boss, uncraftable summon
Progression: No

Stats:
Health: 2,200,000 (3,200,000) (4,080,000)
Attack:
-600 (850) (Melee)
-570 (800) (Fireball, Chlorocurse Bullet)
-620 (875) (Cursed Bullet, Explosive Bullet)
-2000 (5000) (Kingslayer Bullet)
Defence: 85

[All of Ebony's attacks inflict Cursed Inferno - 100%]
[All of Ebony's attacks inflict Energy Surge - 100%]

Attacks:
Phase 1:
Ebony will continuously keep on the move, moving with a mixture of running, jumping, temporary levitation, and teleporting. He will bombard the player with attacks, usually partly-telegraphed by his animations:
If he pulls out his revolver, he will use one of three attacks:
-He will fire numerous shots at the player. The 'cursed bullets' he fires are extremely fast and deal high damage and can also pass through blocks.
-He will fire numerous shots in an arc, starting with the lowest and ending with the highest, though the difference in time even between those two is minimal. The bullets act the same as with the previous attack
-He will fire a volley of explosive rounds at the player. These explode when in close enough proximity with the player, or after travelling a set distance.
If he raises his left hand in the air, he will instead go for a magic attack:
-He may summon numerous fireballs that fly horizontally across the screen. Usually they are summoned farther away from the player, moving towards them. They accelerate as they travel.
-He may release a 'burst' of flames, often dispersing into a complex bullet-hell pattern of fireballs.
-May launch a rapid-fire flurry of fireballs at the player from his hand. Ebony will adjust the trajectory as the player moves, forcing the player to keep moving in order to dodge the attack.
Once down to 65 (70)% health, Ebony will say "Not bad, kid, not bad." before entering his 2nd phase.
Phase 2:
A key difference in this phase is that moving too far from Ebony will inflict the player with Cursed Inferno, and if the player doesn't get close enough still Energy Surge as well. Once the player is close enough to Ebony again, the debuffs are lifted. The distance, however, is quite forgiving.
Ebony retains his previous attacks, though gains new variations of them. He does, however, gain a single new attack.
-Both of the non-explosive bullet attacks gain a variant that uses 'Chlorocurse Bullets' instead. These are a little slower, but have a mild homing effect and thus will curve towards the player as they move.
-He gains a variant of the horizontal fireball attacks where they are summoned at the opposite side of the player from Ebony and move in Ebony's direction instead.
-He gains more patterns for the 'bullet-hell' attack
-He gains a variant of the fireball flurry attack where they are aimed based on the player's movements, though the fireballs in this variant are slower.
-His new attack has him aim horizontally and fire a single bullet. This bullet, called the Kingslayer bullet, can only be fired horizontally and only one at a time, with a lengthy wind-up and cool-down period. The bullet can pass through blocks and can cross thousands of blocks before despawning. The main ability it has is that it deals immense damage, likely killing the player outright, and thus forcing the player to pay attention to Ebony's actions.
Once down to 35 (42)% health Ebony will say "You're tougher than I thought" before entering his 3rd phase.
Phase 3:
Ebony will gain permanent levitation alongside changes to his attacks. He will also teleport a little more often, and no longer needs to use running and jumping to reposition himself.
-Fires more bullets in the cursed, explosive, and chlorocurse bullet attacks
-Gains two more variations of the main fireball attack; one falling from the sky and the other rising from the ground. The horizontal area the fireballs can spawn is immense, however, so just running away won't make you immediately safe.
-Gains more complex bullet-hell patterns for the fireball burst attack. The fireballs also begin accelerating as they travel now as well

Defeat:
Releases a burst of cursed flames, and slowly levitates back down to the ground. Gestures to the player, then disappears.

Drops:
Will drop an endless cursed arrow quiver and an endless cursed bullet pouch. Drops Ebony Embers; materials used for upgrading numerous weapons. Can drop a vanity outfit consisting of his hat, coat, and boots, with the hat separate from his boss mask drop. In Expert he will also drop a replica of his revolver; an exceptionally powerful ranger weapon.

Lore:
An immortal entity bound to an unachieveable goal, roaming the land to find worthy opponents willing to challenge him. Having him answer your challenge is one thing, but gaining his respect is something to be proud of.

Hints:
-Ebony's projectiles deal high damage, but are avoided in different ways. Bullets require speed, while the fireballs require precision.
--Therefore, staying relatively close to see what his next attack is may be advisable
-Dashes prove somewhat effective, but due to the amount of projectiles likely to be moving horizontally, may not be as effective as in other fights
-Don't stray too far from Ebony. It makes it both harder to see his next attack, and puts you at risk of additional debuffs
-His Kingslayer Bullet has a long wind-up and a loud and distinct firing noise. If Ebony's attacks seem to let up for a while, he may be preparing to fire.
--Kingslayer Bullets are ground-restricted in Phase 2, but not in Phase 3. However, they are always only fired exactly horizontally.

Extra Info:
-Ebony has most of his animations already complete, similar to the Sentinel, but has had so for a much longer time.
-- Examples of strung-together firing animations (Drawing, Shooting, Retracting)
-Ebony has a 'western' vibe, made in-part by his wide-brimmed hat, use of a revolver, and his Kingslayer attack being akin to a wild-western showdown.
[Added: 16/6/20]

19 - Crystal Wraith

Appearance:
A somewhat-round grey entity with 4 vaguely branch-like arms protruding from its body. Numerous shiny chunks of red crystal grow scattered across its body, with a larger crystal at its centre. It has 4 eyes and a set of jaws for a face just above the shining crystal at its centre.

Summon: Use the Crystalline Matrix anywhere in the world. Depending on where it is used and the time, some of its attacks may vary. However, the attacks are determined upon summon, and cannot alternate mid-battle. The player is inflicted with Heavy Gravity at the start of the fight.

Fought: Post-Moon Lord
Specification: Post-Blacklight
Special: No
Progression: No

Stats:
Health: 1,000,000 (1,505,000) (1,918,875)
Attack:
-320 (455) (Melee, Floating Crystals, Turret Melee)
-300 (428) (Crystal Shards, Crystal Bullets)
-310 (441) (Electroweb) (Inflicts Red Lightning - 33 (50)%)
-335 (473) (Crystal Deathray, Crystal Blast)*
Defence: 85

[All of the boss' attacks can inflict Energy Surge - 50 (67)%]

• 
  
  Attacks:
  Phase 1:
  In this phase, it moves like Plantera; with three tendrils that end in claw-like turrets and general movement towards the player. The turrets do not shoot in this phase, but still deal melee damage.
  The Wraith has numerous attacks it can use, though when not using any of its 'special attacks', it will continuously shoot small crystal shards at the player. These pass through blocks and can still target the player through walls, unlike Plantera's seeds.
  -It may speed up for around a second, leaving a trail of floating crystals. After a few seconds, all of these crystals will explode, releasing small shards outward randomly in any direction.
  -It may launch 3 large crystals, the same as the 'floating crystals', at the player. These explode into shards on contact with a solid block or after travelling too far.
  -It may summon large floating crystals around itself, all of which explode into shards after around a second. The spawning area for the crystals is quite large.
  -It may summon floating crystals from the turrets at the end of its tendrils. As with the others, these explode into shards.
  -It may launch 8 small red orbs in a ring formation at the player. Red electrical energy connects these orbs to adjacent ones, with the ring gradually expanding. (They all also have a mild homing property in Expert). After a few seconds they will all explode.
  -It may summon numerous red orbs randomly dispersed nearby. After around a second electrical bolts will begin to travel rapidly amongst them for a few seconds. A couple of seconds later the orbs will all explode.
  Once down to 60% health he transitions to Phase 2.
  Phase 2:
  The tendrils break and the Wraith can now move without restriction. The turrets now teleport around randomly, firing burst of 3 shots of crystal bullets at the player, then teleporting again.
  Most of the Wraith's attacks remain the same, though it gains 1 of 4 new attacks based on how it was summoned:
  If summoned at the surface during the day:
  -It will charge up and fire a large deathray for several seconds. It turns to face the player both when charging and firing, though it turns far slower than normal. It does not move outside of just turning until the attack ends. (The Wraith can turn a little faster in Expert, and the beam lasts a little longer)
  If summoned at the surface at night:
  -It will charge up and fire two somewhat-thin deathrays either side of the player, slowly bringing them closer together. The deathrays expire before they close in too far, so it can still be dodged with correct positioning. The Wraith does not turn or move at all until the attack ends. (The charge-up time for the beam is less in Expert)
  If summoned underground during the day:
  -It will summon several large spheres of energy to orbit it, then it will launch them at the player one-by-one. These 'crystal blasts' create damaging explosions as they travel, pass through blocks, and do not despawn for a long time. (More are spawned in Expert Mode)
  If summoned underground at night:
  -It will launch 4 'crystal blasts' out in the cardinal directions, and then 6 more afterwards that are all evenly-spaced. (In Expert Mode it also fires a 7th directly at the player during the 2nd volley)
  Once taken down to 25% health it will enter Phase 3
  Phase 3:
  The Wraith's turrets will begin to orbit the main body as opposed to teleporting around randomly. The still fire shots in volleys of 3, attacking independently of the Wraith
  The Wraith moves faster, but does not gain any new attacks in this phase. (It attacks more frequently in Expert Mode, however).
  
  Defeat:
  Explodes into gibs, releasing numerous red and pink particles as it does so.
  
  Drops:
  Phantom Ruby Shards; a material used for making a fairly large assortment of weapons. Can also drop these weapons directly, such as a sword, spear, flail, tome, bow, gun and a summoner staff that summons a crystal minion. Will also drop one of 4 accessories based on when it was summoned: Wings, A dash-granting accessory, a shield, or a stat-boosting accessory respectively. In Expert Mode it drops its crystal core which, if the player is damaged, will launch a flurry of crystal shard projectiles at the enemy that damaged them.
  
  Lore:
  A phantom constructed of large pieces of etherial crystal. It seems to get all its power from the crystal on its back. Its goal is unknown, though it seemed determined to continue adding to its form with more and more crystals.
  
  Hints:
  -Its new Phase 2 attack and its accessory drop are based on when and where it was summoned, not fought. If you want to face it above-ground but want either of the latter accessories, you could summon it and then bring it to the surface, or vice-versa.
  -Since many of its attacks consist of lots of small projectiles and a notable amount of potential RNG, having a Rod of Discord handy may be recommended.
  -Despite its Phase 1 being similar to Plantera, it does not enrage at the surface like she does
  
  Extra Info:
  -Originally, it was going to have a more green-ish and 'natural' palette, but then it seemed too similar to Plantera and thus it was altered
  -- The original, more 'earthly' palette; with an orange-brown body and green crystals.
  [Added: 16/6/20]

20 - The Revenant

Appearance: A large spectre made of writhing, translucent ectoplasm. It has a wispy flowing 'tail' surrounded by large crystal-like structures. It has a large mouth lined with teeth, and seemingly a second set of constantly-moving jaws within as well. Its body is covered in large white pustule-like growths, though these are actually its eyes. Veins cover its body, despite being a ghost, which pulsate and writhe constantly.

Summon: Use the Spectral Amalgam in the Dungeon at night. The Amalgam is actually dropped as an item once the player kills enough Dungeon Spirits after Behemoth's defeat and isn't craftable. After using it, the boss will spawn after 15 seconds. It can be taken out of the dungeon, but if it becomes daytime it will enrage; becoming almost impossible to kill.

Fought: Post-Moon Lord
Specification: Post-Behemoth
Special: Secret boss, Uncraftable Summon, Returning Boss
Progression: Later Bosses

Stats:
Health:
-3,000,000 (4,865,000) (6,202,875) (Revenant)
-500,000 (750,000) (956,250) (Ecto Heart)
-200,000 (325,000) (414,375) (Ectospawn)
-20,000 (25,650) (32,704) (Tongue)
Attack:
-700 (965) (Revenant Melee) (Inflicts Ethereal Affliction - 100%)
-620 (875) (Ectospawn Melee, Spectral Flame Bomb)
-600 (850) (Phantoms, Phantom Flames, Spectral Cluster, Wraith)
-0 (0) (Tongue Grab) (Inflicts Tongue Leech - 100%)
Defence:
-80 (Revenant)
--99,999 (Enraged Revenant)
-100 (Ectospawn)
-120 (Tongue)

[All attacks inflict Ethereal Affliction - 50 (100)%]
[Once enraged, all attacks will deal 10,000 damage instead of their regular damage]

Attacks:
Phase 1:
Usually attempts to stay near to the player, floating near them, while unleashing its numerous attacks.
-It may charge at the player, teleporting to a new location after the charge. It may charge again after teleporting, and this cycle can repeat up to 5 times.
-It may launch a lengthy barrage of Phantoms from its mouth. These projectiles are large, pass through blocks, and accelerate as they move. Revenant re-adjusts its aim as it releases them to force the player to keep moving.
-It may summon horizontal and vertical bullet-hells of phantom flames; ghostly fireball projectiles that pass through blocks.
-It may fly around, but not at, the player, spawning spectral clusters. There are 2 variants of these; some that slowly chase the player, and the others that are stationary. This attack can be a mixture of both types.
-It may roar, causing phantoms to rise from beneath the player, but at varying angles
-It may line up either horizontally or vertically with the player, continuously launching phantoms at them.
-It may launch a spectral flame bomb from its mouth; a homing projectile that explodes after a few seconds, releasing phantom flames outward in all directions randomly in a single 'burst'.
-It may release phantoms from its body in random directions rapidly for a few seconds.
-It may charge at the player, releasing spectral clusters as it moves. These will either all be stationary ones, or all chasing ones; not a mixture.
-It may teleport to random places, launching arcs of 7 phantom flames after each teleport.
-It may summon up to 5 horizontally moving 'pillars' of phantoms. These may either have all the phantoms spaced out so the player can dodge between them, or they may be too close together to evade, but have a large gap somewhere in the pillar for the player to get through. All of them will travel in the same direction.
-It may release numerous wraiths from its mouth. These look similar to the phantom projectiles, but are larger and instead of accelerating will home-in on the player until they despawn.
-It may charge at the player, summoning wraiths as it travels.
Once taken down to 60 (65)% health, the Revenant will enter its 2nd phase.
Phase 2:
The Revenant will release 5 (6) Ectospawn from its mouth, and will then disappear. Ectospawn look like smaller, less disgusting forms of the Revenant, and lack most of its complex attacks.
Ectospawn have only 2 attacks, but they get stronger the more that are defeated.
-They may charge at the player. Each Ectospawn killed increases the distance the charge can travel
-They may launch phantoms at the player. Only 1 can be launched at the start, but this number will increase by 1 for each Ectospawn killed.
Additionally, for each Ectospawn killed, the others' attack frequency increases. This means that at the start they have sheer number advantage, but later-on they will be faster and more aggressive.
Once all 5 Ectospawn are killed, Revenant will re-appear and Phase 3 will begin
Phase 3:
Revenant will re-appear, though it will summon an Ecto Heart as it does so. Revenant is invulnerable in this phase, requiring the player to target the Ecto Heart, though Revenant will destroy any projectiles that hit it so that it can better protect the heart.
Revenant generally attacks slower in this phase than in Phase 1, but retains all of its previous attacks. It gains a couple of new ones as well.
-It may launch a long, ghostly tongue at the player. If it grabs the player, their health will slowly be drained until the tongue is killed. Additionally, the tongue will slowly pull the player towards the Revenant.
-It will charge at the player, and then teleport back to where it was before the charge started. It then launches an arc of 13 phantom flames at the player
The Ecto Heart will stay close to Revenant, but will attempt to keep away from the player if it gets hurt or the player gets too close. It cannot attack on its own and is entirely dependent on the Revenant for protection.
Upon killing the heart, the Revenant will freak out, and it will fall to the ground. Phase 4 will then begin.

20 - The Revenant (Continued)

Phase 4:
The player is inflicted with Heavy Gravity throughout this phase.
Revenant will begin on the floor, motionless, and still invulnerable; seemingly defeated.
After a few seconds it will begin to shake before numerous spider-like legs burst out from its sides, and Phase 4 truly begins. It becomes vulnerable once the spider legs protrude from its body and starts moving.
The Revenant now scurries at the player very fast, able to both move and accelerate rapidly. Its movement speed can reach 120 mph, far faster than even the Black Spot mount, though it rarely reaches this speed due to having to change direction. It retains only a few attacks from before, and some new ones based on the sudden fighting style change:
-It retains its horizontal and vertical bullet-hells, as well as the wall of phantom attacks.
-It may align itself with the player vertically and begin launching phantoms upward at them. It moves with the player, forcing the player to continue moving to dodge the attack.
-It may jump 3 times in succession, similar to biome mimics, but with much greater height and distance.
-It may perform a single giant leap at the player. This attack can pass through blocks and can gain immense jump height.
-It may teleport, pretending to burrow into the ground before re-appearing near the player with a vertical leap.
Once down to 40% health it will enter its 5th and final phase.
Phase 5:
Phase 5 is almost identical to Phase 1, though it is more aggressive and retains the two new attacks from Phase 3.
It may also infrequently release a single Ectospawn. These Ectospawn are only as strong as the unboosted Phase 2 variants, with short-ranged charges and single Phantoms for their projectile attacks, but can act as additional obstacles for the player. They have a cooldown time of 30 (20) seconds before Revenant can spawn a new one.

Defeat:
Roars, begins to explode, and disappears with a light blue flash of light. It leaves long-lingering light blue particles where it died. All live Ectospawn despawn upon Revenant's defeat, as well as its Tongue if it's currently active.

Drops:
Always drops Ethereal Remnant; a crafting material used for an abundance of late-game items. Also drops a sword, a flail, a summoner staff that summons mini Ectospawn, a summoner whip, a tome that launches phantoms, a magic staff that launches phantom flames, a gun, and a bow. It may also drop a Phantasmal Crystal; used to craft jetpack-like wings. In Expert Mode it additionally drops the Revenant's Spirit; an accessory that summons an Ecto Heart to float behind the player. The player cannot be hurt directly, with the Ecto Heart instead acting as the player's damage hitbox. This means the player can themselves block non-piercing projectiles with their own body, and their hitbox is generally a little smaller, though since it lingers behind the player a little when it comes to movements it may be hard to get used to.

Lore:
An amalgamation of hundreds and thousands of spirits seeking revenge upon you. Almost every entity you've slain found their souls called to the dungeon, so that the Revenant could form... and get its revenge upon you after death.

Hints:
-Spending some time getting used to the attacks in Phase 1 may be recommended, as most of these get re-used in Phases 3 and 5.
-While the item can only be used in the dungeon, the Revenant can be taken out of the dungeon without any problems. Therefore, it's likely best to summon it close to the dungeon entrance and to just run back outside to give the player more dodging room.
-Instead of killing the Ectospawn one at a time, it might be wise to try and lower their health equally, and to try and kill them all in rapid succession. This would mean that it would minimise time spent dealing with their stronger variants, as they would already have low health by the time they get stronger.

Extra Info:
-The Revenant was a boss from Boss Ideas 5, brought back again and overhauled with a new sprite.
--Its transformation ability, while altered, returned for its Phase 4, and its tongue attack returned for Phase 3. Some of the more basic attacks also returned, though with changes to projectile properties.
-Since the Revenant is an amalgam of souls, it retains some features of other bosses:
--It has a physical appearance similar to EoC, uses, EoW's 'splitting' mechanic for Phase 2, uses BoC's 'minion invulnerability' and teleporting, uses a tongue similar to WoF's and Moon Lord's for one of its Phase 3 attacks, for example.
-Only counting Vanilla, the player would need to kill a minimum of 417 kills to complete regular Terraria: Skeletron, a Voodoo Demon, WoF, a minimum of 3 regular enemies for the mech boss summons, the mech bosses themselves, Plantera, Golem, the 4 dungeon cultists and LC, 400 celestial enemies and the 4 pillars, and finally the Moon Lord. This excludes Expert Pillar changes, anything from the Boss Ideas themselves in terms of necessary progression, or general enemy or boss minion kills. Therefore, even with minimal kills, Revenant's lore entry can still apply.
[Added: 18/6/20]

Final Notes

So this concludes Part 1 of Boss Ideas 10. Took a while to finally get out, though hopefully it will have been worth the wait.

Part 2, while partially in production, will likely take some time simply due to some of the bosses I'd want to include having large and complex sprites and patterns that need planning, alongside other projects I'm working on. Hopefully, I'll get it done in a reasonable time though :P

https://discord.gg/424nqd
Boss Ideas Discord is still up. Admittedly somewhat quiet as of recent, but at least I've somewhat organised it coherently at last :)

An additional shout-out to Phantasmental for being willing to make some of the bosses' themes in this one! They're a cool dude and so I'd like to recommend checking out some of their songs; both ones listed here and others on their Soundcloud and YouTube!

Anyways, I hope you enjoyed, and I'm sorry if any of the bosses' fight descriptions were an assault on the eyes with all the text, and I'll see you for whatever the next Steam page will be... maybe a new Lorekeeper entry?

Anyways, see ya then :)

[Twylitefox]

meme dog is trash
he should try to fight SPCL



deal with it

[CaptainGumball7]

━━━━╮ This is memedog. Help
╰┃ ┣▇━▇ memedog take over
 ┃ ┃  ╰━▅╮ Steam by pasting
 ╰┳╯ ╰━━┳╯ him in other
  ╰╮ ┳━━╯ comment sections or he
 ▕▔▋ ╰╮╭━╮ will never be a meme dog
╱▔╲▋╰━┻┻╮╲╱▔▔▔╲
▏  ▔▔▔▔▔▔▔  O O┃
╲╱▔╲▂▂▂▂╱▔╲▂▂▂╱
 ▏╳▕▇▇▕ ▏╳▕▇▇▕
 ╲▂╱╲▂╱ ╲▂╱╲▂╱

[Twylitefox]

i honestly feel like the twisted cosmic dragon sprite should be the normal cosmic dragon sprite, but what do i know.