Lohezet

Lohezet ignores a creature's resistance to Poison damage.

Lohezet makes three Withering Blast attacks and uses Miasma if it's available. He can replace one of the attacks with a use of Spellcasting.

Melee or Ranged Spell Attack +9 to hit, reach 5 ft. or range 60 ft., one target. 18 (2d12 + 5) Necrotic damage.

Lohezet magically conjures a billowing cloud of purple fog in a 20-foot-radius sphere centered on a point within 120 feet of himself. The area within the sphere is heavily obscured, and when a creature starts its turn in the sphere or enters the sphere for the first time on a turn, it must make a DC 17 Constitution saving throw. On a failed save, the creature takes 39 (6d12) Poison damage and is Poisoned until the start of its next turn. On a successful save, the creature takes half as much damage and isn't Poisoned. The cloud lasts for 1 minute, until Lohezet ends it early (no action required), or until Lohezet uses this action again. A strong wind disperses the cloud.

When a creature within 60 feet of Lohezet damages him, Lohezet magically retaliates with a spray of foul, purple mist. The creature must make a DC 17 Constitution saving throw, taking 16 (2d10 + 5) Poison damage on a failed save, or half as much damage on a successful one.