Avatar of Myrkul

Grave Magic. When the avatar casts a spell that deals damage, it can change the spell’s damage type to necrotic.

Incorporeal Movement. The avatar can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Innate Spellcasting. The avatar's innate spellcasting ability is Intelligence (spell save DC 19, +11 to hit with spell attacks). The avatar can innately cast the following spells, requiring no material components:

At will: animate dead (as an action), detect magic, light, mage hand, message, misty step, prestidigitation, ray of enfeeblement

3/day each: dispel magic, fireball, invisibility

1/day: resurrection (as an action)

Legendary Resistance (3/Day). If the avatar fails a saving throw, it can choose to succeed instead.

Turning Immunity. The avatar is immune to features that turn undead.

Multiattack. The avatar makes two Scythe of Myrkul attacks. It can substitute Cold Embrace for one of these attacks.

Scythe of Myrkul. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 11 (3d4 + 4) slashing damage plus 27 (6d8) necrotic damage.

Cold Embrace. Ranged Spell Attack: +11 to hit, range 120 ft., one target. Hit 24 (4d8 + 6) necrotic damage, and the target can't regain hit points until the start of the avatar's next turn. The target must succeed on a DC 19 Constitution saving throw or have its hit point maximum reduced by an amount equal to half the necrotic damage taken, rounded down. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Negate Spell (2/Day). When the avatar sees a creature within 60 feet of it casting a spell, it tries to interrupt it. If the spell is 4th level or lower, it fails and has no effect. If the spell is 5th level or higher, the avatar makes an Intelligence check (DC 10 + the spell’s level). On a success, the spell fails and has no effect.

The avatar can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. The avatar regains spent legendary actions at the start of its turn.

Death Eater. The avatar targets one friendly Undead creature within 10 feet of it and consumes it. The avatar regains hit points equal to half the target creature's total hit points, rounded down.

Reaper's Scythe (Costs 2 Actions). The avatar makes one Scythe of Myrkul attack.

Gaze of the Dead (Costs 3 Actions). The avatar fixes its gaze on one creature it can see within 30 feet of it. The target must succeed on a DC 19 Wisdom saving throw against this magic or become frightened for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target's saving throw is successful or the effect ends on it, the target is immune to the avatar's gaze for the next 24 hours.