The Magistrate

The Magistrate is a a special type of Piglin that only spawns when you kill every Piglin in the village. 
Summoning
Conditions: You need to be in the Nether, and you must be in the village when you kill the last Piglin. 
Bossfight
When it spawns in, it has 175 hp. It looks like a Piglin mixed with magma and netherite. It weilds a Netherite sword. It runs slightly faster than the player.
Attacks
It can swing its sword when you are close enough. It can summon a ghast fireball if you are out of range. It can throw lingering potions of blindness and slowness.
Defenses
It can hold up a Netherite shield.
Strategy
You can build an obsidian pillar to rise above the sword range and dodge the ghast fireballs. You can hit it with your sword until it dies.
Loot
The Magistrate drops 3-5 Netherite Bars and his Netherite Shield.
Credits
This was made up by me :)