Bloodheart

Far Realm Parasite. Inside the lich’s torso dwells a wormlike parasite that contains the lich’s soul. When the lich dies, it implodes into the parasite, which then vanishes into the Far Realm. In 2d4 days, the parasite causes the lich to reappear within 1d4 miles of where it died. If the lich died inside a magic circle cast to contain Undead, the lich instead reappears as an otyugh with all the lich’s memories.

Unusual Nature. The lich doesn’t need air, food, drink, or sleep.

Multiattack. Bloodheart makes one  Tentacle Swarm attack or uses Spellcasting. Bloodheart also uses Scythe Hands twice.

Scythe Hands. Bloodheart's hand's fall out and in their place are 2 scythes. He must get a D15  or more on his roll.

Spellcasting. Bloodheart casts one of the following spells, using Charisma as the spellcasting ability (spell save DC 17):

At will: detect magic, mage hand, prestidigitation

2/day each: dispel magic, hunger of Hadar, lightning bolt

1/day each: arcane eye, dimension door, plane shift (self only)

Tentacle  Swarm.  Bloodheart's 4 tentacles attack all players, using Strength as the bonus.

Darkness Overload. Bloodheart makes everything dark so you cannot see anything, and if there's a sorcerer in the batch, he removes the spell "Light". He will then pin you to the wall and suck the life out of you. You have 20 seconds to roll and you must get 15 or more.

Duel. When out of his cave, Bloodheart will challenge the strongest character to a duel. Then the second best, and so on and so forth, using Strength as the bonus.

Far Realm Step. Immediately after taking damage, the lich, along with any equipment it is wearing or carrying, magically teleports up to 60 feet to an unoccupied space it can see.