Ygorl, Lord of Entropy

Each creature that is not a construct or undead that ends its turn within 15 feet of Ygorl takes 14 (4d6) necrotic damage.

If Ygorl fails a saving throw, it can choose to succeed instead.

Ygorl has advantage on saving throws against spells and other magical effects.

Ygorl's innate spellcasting ability is Charisma (spell save DC 23, +15 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

At will: blight, blink, chaos bolt*, detect magic, fly, shield

3/day each: circle of death, enervation*, symbol (discord only)

2/day each: finger of death, harm, mental prison*

1/day each: power word kill, power word stun, symbol (death only), weird

* Spell from Xanathar's Guide to Everything

Ygorl makes three attacks: two with its scythe, and one with its Entropic Touch.

Melee Weapon Attack: +14 to hit, reach 10 ft., one creature. Hit: 18 (2d10 + 7) slashing damage plus 19 (3d12) necrotic damage. Any creature reduced to 0 hit points by this attack dies, with its body and everything it is wearing and carrying, except magic items, exploding into a cloud of ash. The creature can be restored to life only by means of a wish spell.

Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 16 (2d8 + 7) necrotic damage, and the target must succeed on a DC 22 Constitution saving throw or gain one level of exhaustion.

Ygorl summons 1d4 + 1 death slaadi. A summoned slaad appears in an unoccupied space within 60 feet of Ygorl, acts as an ally of Ygorl, and can't summon other slaadi. It remains for 1 minute, until it or Ygorl dies, or until Ygorl dismisses it as an action.

Ygorl teleports, along with any equipment it is wearing or carrying, up to 120 feet to an unoccupied space it can see.

Ygorl makes one attack with its scythe.

Ygorl uses its Teleport action.

Each creature that is not a construct or undead within 30 feet of Ygorl must make a DC 22 Constitution saving throw against the lord of entropy's attempt to unmake life, taking 42 (12d6) necrotic damage on a failed save, or half as much damage on a successful one. Ygorl then regains a number of hit points equal to half the total damage taken by all affected creatures.