[Plains of Eidolon] The Great Eidolon Hunt Achievement/How to kill the Teralyst

A basic guide to get the "Great Eidolon Hunt" achievement and how to farm them

1. Preparation

Disclaimer: Since at my time it is still fixing a lot so i will update pictures and more info in the future.
To get the achievement you must deliver the killing blow to boss

1. Teralyst is the big walking colossus wander out of the Plains at night. It will be immune to all warframes powers and warframes weaponry when its SHIELD (blue) bar is present. This shield can only damaged by operator's Void Beam (default is RMB in Operator mode).
   AS OF U.22.0.3: The Teralyst will now no longer be affected by Auras that manipulate its max Health and max Shields.
   
   Corrosive Projection still does work however, tested
   
   
2. My setup to run this fight (will update with picture later):
   1. Harrow Covenant buff build.(can be replaced with any of the below)
   2. Trinity Bless (Essential to protect team as well as lure machines)
   3. Rhino Roar Build/Octavia Opera Build ( having both is highly recommended)
   4. Ivara Artemis Bow Radiation build/Chroma DPS build (having one is enough)
   
   Also, having a good Amp Weapon for your operator is recommended in damaging its shield. It will speedup the process greatly in farming.
   
   Skilled players can solo/duo this boss, the setup for this is Chroma + Trinity Bless. I tested and it is not so hard with proper gear.
   
   
   And a good weapon, with Radiation/Puncture/Ice Damage modding is also a bonus (Lanka, Vectis,or any sniper of your choice since they stack combo damage). Teralyst is a bullet sponge so you need something efficent and effective to shot at.

2. Engaging the boss

1. Before engaging the Eidolon, i recommend each one in your squad take some Eidolon Lure machine (can be found throughout the plain at night near Grinner Camps) and let them follow you. It will help in the fight later. You can also assign one person to control all the Lures (Trinity Bless is a good choice).
   
   
   
2. When first encounter the Eidolon, dont use your warframe to aggro the boss. Stay close to it about 100m and all the team can use operator mode to start chipping its shield off and avoid damaging the warframes.
   
   
3. The operator can use Void Mode (default is [Left Ctrl]/[C]) to dodge all of its skills.
   
4. Teralyst will begin to spawn mobs. These mobs can be CC but again only the operator beam/amp weapon can destroy it.
   HAVE ONE PERSON TO HANDLE ALL OF THEM, ELSE THE MOBS WILL HEAL THE TERALYST's BLUE SHIELD. The rest can keep focus on teralyst.
   If you gather a lot of eidolon lure, they can help you. These lures will instantly "absorb" Volumatyst (the mobs) once their shield is gone, so you just need to damage 'em by warframe, and dont need to switch to operator
   
5. Once shield is depleted the teralyst will flash red briefly with a "shut-down" sound effect and you can switch back to your Warframe to damage it now.
   
6. Teralyst must be damaged in all 4 parts: 2 Knees, 2 Shoulder. Once all four is destroyed it can be exposed to the head health bar to truly kill. The Damaging order is Knees/Shoulder(any of 4)>Head.
   
7. After damaging the first part (Right Knee) it will teleport away to regen shield (kinda like Monster Hunter, lol). If you have bring the eidolon lure, these lure can block boss teleport so i highly recommend taking em near the boss when one part is destroy and have them hold position.
   
8. The eidolon will also emit massive Magnetic-damage wave AOE when one part is destroy (Energy spike warning by Onnko) so when it does, get away from it fast. Harrow with duration build can also cast 4 with proper timing to let the team stay close to keep track of the Eidolon. You can also use Void Mode in operator form to dodge.
   
   
   Example of how much damage it can dealt. Normally it can shred 5000 ferrite armor Rhino as well as a Chroma, so do not attempt to face-tank it.
   
   *In case the eidolon teleport away: All 4 spread out and search for it.
   Pay close attention to its glowing light pillar, scream and loud rumble footsteps. If one does encounter it, mark the Teralyst so others can go to its place again.
   
9. The battle flow is roughly the same: Operator damaging the shield, Person will CC keep killing mobs which spawn to keep its shield from generating, and switch back to warframe to damage it when shield is gone.
   
10. If you have taken the Eidolon Lures with you and protect them, they can negate boss teleportation allowing the fight going seamlessly.
    
    
    Once the 3rd part (shoulder) is destroyed it will summon hail storm.
    
    

A slightly different strategy is damaging all the part to extremely low health but not breaking them, in order to buy time to gather enough lures (since sometimes lures can be far away from boss location and they might even bug pathing). Once you get enough lures (2-4) to the location you can start destroying its limbs. In my experience the damaging get super easy once you get a proper party, each night we can hunt for 3-4 eidolons.

3. Finishing the Teralyst

1. If all the parts is gone, the Teralyst will begin to summon mobs to heal it and emit a weaker damaging AoE. Trinity must bless throughout this duration.
   
2. ALL OF THE SQUAD FOCUS ON KILLING HEAL MOBS.
   
3. Once it is done, boss expose its head health bar. All the shots are now count as headshots so Harrow'4 will work wonders. Shot it and voila, loot!

*Additional note on how to get Brilliant Eidolon Shard, thanks to /u/FishyFish1

How to capture the Eidolon:

Destroy his 4 limbs and get to the final phase. Leave him at low HP to make the capture easier

Find a grineer camp nearby and get two Eidolon Lures.

Charge up the Eidolon Lures by killing the little drones near them.

The 2 Lures will now attach to his 4 destroyed limbs, now you can kill the eidolon.

After killing it with the 2 lures attached it will start floating in the air for a second and then drop down underground, the drops might not spawn where it died but somewhere near. The Brilliant Eidolon Shard drop will look something like this (with an actual model), now head back to Cetus and get your shard.

EDIT: You can use the lures right at the start so that he won't teleport after destroying every limb, I recommend having a bless trinity to keep them alive.

Happy Hunting Capturing, Tenno.

My english is not good so thank you for reading this far. Also,if you have contribution, please comment and i will add it to the guide. Again, good luck!

[SL33pr]

Updated to the latest build.

[Ruby Rose]

Shield Disruption & Corrosive Projection no longer works on the Teralyst.

[Rom@n DeaD™]

Thank you!

[luca]

Primed Vibrator < Primed Dildo

[Half Life 1 Scientist]

if you do not deliver the killing blow to the teralyst, you will not get the achievement

[Goat Screams]

This guide is amazing, your english is fine, and you should feel good.

[Domesticon]

Good guide, man, thanks for the info

[fdmct]

Aaah okay

[SL33pr]

You farm eidolons to get cores, these core can use to trade for Quills standing

[fdmct]

What do you get from it besides the achievement?