For this to work, you need the Origins Mod.

This is a Datapack, not a Mod. 
You are able to choose a different character to become your origin to experience Minecraft.

Story:
In a magical world, someone can revive from death, someone can create things with water, someone rescued by the Ender Dragon, there have even a lot of things would happen here.
But all of the sudden, a powerful being existed for an unknown reason. He hated all being and challenging every mortal in all dimensions. And he names himself - Demon King.

The owners of the Tree of Time, the leader of the pillagers, and even the king at The Nether notice that this strong being was making trouble and affecting them in different ways.
Even though they never collaborate or interfere with each other. This time, they all have one goal, which is to meet and do something with this "Demon King".

Boss Origins:

Featuring:

Demon King

In a world with magic, a powerful being existed for an unknown reason. He hated all being and challenging every mortal in all dimensions. And he names himself - Demon King.

Demon- You have more health, But double fire damage and burn under the sun when without a helmet.
Dash- You can dash in different directions by moving and pressing sneak.
Mortal Souls- You can get different abilities by killing different hostile mobs, including:

>Fighter Soul- hostile mobs with mostly flesh.

>Carapace Soul- hostile mobs with mostly shells.

>Arthropoda Soul- hostile mobs with mostly bone.

>Sharp soul- hostile mobs with mostly spike.

>Wither soul- Wither.

>Dragon soul- having a dragon egg in your inventory.

-Mob list for Demon King:

zombie husk drowned creeper ghast evoker pillager vindicator hoglin ravager zoglin magmaslime slime piglinbrute piglin zombifiedpiglin phantom enderman spider cavespider witch vex - Fighter Soul > Strength
endermite silverfish shulker - Carapace Soul > absorption
skeleton stray witherskeleton blaze - Arthropoda Soul > resistance

elderguardian guardian - Sharp Soul > throns
wither - Wither Soul > apply wither on hit
enderdragon - Dragon Soul > regeneration
player - Player Soul > totem of undying effect once, cause entity around

Other Boss Origins:
Piglin King

Raid Leader

Normal Origins:

Featuring:
Forgotten Armor

The soldiers fight for their lord in life, then again in death, even the soldiers dead, the armor still fighting. Forever.

Living Armor- Gain one "Armory Body" stack every 30 seconds. Consume one to negate the next attack's damage. You have fire resistance. But only have one health. No need to eat.
Self Upgrade- By default, you only have 2 max stacks of "Armory Body", Armor won't give you defense, but increasing the max stack of "Armory Body", Except leather and golden( Golden armor makes your "Armory Body" cooldown faster).
Learn from Master- Different weapons give you different power. Power level increases based on the material.

>Sword- Receive speed when hit.

>Axe- Higher attack damage.

>Bow- Receive speed when charging, receive a decay speed boost when shot.

>Shield- Receive absorption when using.

Soul Force- When using the Primary or Secondary key, you are able to drag or push the entities around, but your attack will reset the cooldown.
Heavy- You sink in water.
Cursed Soul- Villager and Iron Golem don't like you.

Other Normal Origins:
Weapon Master

Masked Girl

Ender Fury

Nameless Swordmen
Rosutsu

All origins are coded from 1.19.2, didn't test on another versions, you can try if you want.

Any questions can ask me from my discord ::: )
Discord : Ten_Mic_10#8198

The Forgotten Magic Origin