Warning: This mod is not for the faint of heart, it will take you many many hours just to level up to the max level and even more to unlock every item/skill. It took me 252 in game days to get to level 82 before I found a infinite exp exploit to get level 100 in just a hand full of days. It's also completely overpowered which is a massive turn off for many people.
Note: I will be using my own names for things for a better translation.

Hanger - 100 Sanity - 75 Health - 50
x2 hunger drain and x2 sainity drain when not near other players.
Most passive mobs will ignore you.

Small dagger: Infinite spear. Gives a +10% speed boost while holding it.
Bracelet: +12 slots. Unspoiles food. Provides as much cold protection as a puffy vest. Lets other players craft and use chef equipment.
The Flag: Can cast a spell that makes all nearby survivors deal 25% more damage for a short while. You will not be needing this if you are soloing.
The cane. I think somehow it can be used to teleport someway. [Needs verification]

You gain exp by Killing stuff. The bigger the better. Bosses only give 50% exp if you did not land the killing blow but still dealt damage.
Each level gives you +1 to all stats and slightly increases your damage multiplier. Leveling up unlocks more survivor crafts.

Children's Meal Set - Berries, mushroom, honey, big meat - Only kid raphtalia can eat it. Gives 115 hunger 100 sanity 50 health.
Ball: Gives 15 sanity per minute while equipped. Deals no damage unless you hold down the button to charge it. Useful for hunting koalefant.
The sword: You can pick it up once you are level 10. Spawns randomly around the map. Infinite spear with extra range.

There are key binds for each skill in the mods setting. These can be changed at anytime.
At Level 10 the mirage skill is automatically learned. Causes you to become invisible to all enemies. When you unlock the adult form later, while invisible and using the sword you can backstab a target for x3 damage.
After killing a couple of balloon monsters, you can craft the light spell. It spawns a light source that gives sanity when near. Keeps shadow hands away from fireplaces.

Once you reach level 30, you will no longer earn exp until you craft the hourglass thing and pay 100 gold to it to remove the level cap.
You WILL be killing dragonfly, not once but twice. With a character with basically no hp. If you have friends, grab your flag and start buffing everyone. If you are soloing, learn to make gun powder.
Once placed, you can teleport to it from anywhere on the map.

Along side allowing you to earn exp again, paying 100 gold also unlocks your adult form.
Adult form does not suffer from a x2 hunger/sanity drain and can use attack spells.
(Lore-wise it gets a bit confusing but this called upgrading your class into an 'advance' class, they do this in the show to gain a new skill and extra stats. Neither the manga nor the anime gave raphtalia's class an actual name.)
Doing this also gives you a mask. Its just a shadow amulet for the head slot, meaning you can wear body armor and making it much safer to use then an actual amulet. It can be refilled by bananas??? and will not be need for anything.

The sword can be upgraded when put inside of the hourglass thing.
1st upgrade - +20 damage.
2nd upgrade - +10% faster while equipped. Very slight range increase.
3rd upgrade - Becomes a multipurpose tool. Can chop and mine (looks very stupid but to be fair, I too would break a bolder in half if I could).
4th upgrade - +30 damage.
You need to complete all normal upgrades first before being able to use the shadow sword upgrades.

The following can be upgraded in any order.
10 blue gems, 40 ice, 10 nightmare fuel - +20 damage. Attacks now freeze the target.
1 Bee Queen Crown, 20 honey, 40 stingers - Attack now deals aoe damage in a small area.
10 rubies, 40 charcoal, 10 nightmare fuel - +20 damage. Attacks now apply a debuff that causes enemies to take 20% more damage from all players.
5 orange gems, 5 living logs, 10 nightmare fuel - +10% faster while holding it. Chop trees down and mine rocks instantly.

While in adult form - Star Blade: Deals [200] damage in an aoe in a direction in front of you.
After reaching level 40, you can upgrade the light spell into the advanced light spell - The light now follows you around as you walk. Gives more sanity, burns brighter and lasts longer.
After reaching level 60, you automatically learn the Heavenly Sword Technique - Deals [1000] damage in a small direction in front of you. Long cooldown.

After unlocking the adult form - Upgraded small dagger: Can be used to teleport anywhere on the map. Opens a temporary wormhole for your friends to use.
Flag+ - Increases damage buff to 50%. Survivors under this buff now deal electrical damage and move 10% faster.
Sword Sheath - Provides all the benefits as the bracelet. Instead of providing cold resistance, it provides heat resistance. While holding both the sword and the sheath, right click yourself to "sheath your sword", while sheath'ed you move 10% faster and slowly recover your hp over time. After a short charge time, unsheathe your sword causes it cause it to deal 50% more damage for a short while.
After reaching level 40, you can craft the Brave Amulet - When your hp drops to 10%(about the 30-50 mark), you gain a invincible shield for a couple of seconds. Not very useful. It can be used to revive like a life giving amulet. Reviving increases damage by 100% for a short duration after reviving. Unfortunately it drops your stuff on the ground.

Some mini bosses drop bonus items when killed. They are generally useful early on but you will probably drop them later.
Witch costume - Dropped by klaus. Armor slot. Reduces damage by 90% and infinite durability. Provides as much cold resistance as a puffy vest and prevents wet.
Eye of True Sight - Dropped by the eyes of terror. Head slot. Gives your attacks a chance to deal critical hits. Attacking from behind increases this chance. Critical hits deal x2 damage. Has two modes. Damage mode: causes your critical hits to deal slightly more separate damage based on how much hp the boss has. Sabotage mode: Your critical hits to reduce the bosses damage by a lot for 3s.
Gun. Dropped by the mechanical eyes of terror. Its a gun. I dont remember this being in the show. Can be repaired with gold, gears or wires. The smoke screen will prevent enemies from locking on to you as long as they are attacking something else.

Not the average players cup of tea.
1 Gnarwail Horn, 1 Rainbow Gem, 10 Nightmare Fuel - ??? I think it increases your damage while on a boat.
3 Pure horror, 5 Dreadstone, 3 Dark Tatters - Dealing damage increases your range and damage temporally. Resets whenever you take damage.
5 Pure Brilliance, 5 Brightshade Husk [Vilification needed], 1 Fragment of the Crown of Enlightenment - Now deals +20 planar damage. Small range increase. Sometimes summons a gestalt to help you attack.

Most of this stuff you will just see it happen and dont need to remember.
Level 30 - Kid form harvests plants and crafts items instantly.
Level 40 - Anything you can harvest now gives x2 more when picked in kid form.
Level 50 - Adult form now recovers hp over time. Kid form moves 10% faster.
Level 60 - Crock pots now give x2 of what ever you cooked when in kid form. Adult form now will no longer be stunned or slowed by enemies attacks when below half hp.
Level 70 - Cheaper crafts while in kid form.
Level 80 - Anything killed in adult form now drops x2 more items from their loot table.
Level 100 - Attacks now ignores all types of armor. By now your total stats will be 250 each.