Blood Angel

Innate Spellcasting. The blood angel’s spellcasting ability is Wisdom (spell save DC 17). The angel can innately cast the following spells, requiring no material components:

At will: pass without trace, cause fear, thaumaturgy, hunter's mark

1/day each: commune, hallucinatory terrain, dominate person, insect plague, evard's black tentacles, life transference

Magic Resistance. The blood angel has advantage on saving throws against spells and other magical effects.

Hunger for Blood. When the blood angel does necrotic damage to a creature with blood, they restore hit points equal to half the necrotic damage they deal. 

Multiattack. The blood angel makes two melee attacks.

Blood Claws. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 10 (1d8 + 6) slashing damage plus 18 (4d8) necrotic damage.

Consume Life (1/Day). As a bonus action, the blood angel can force a creature it is grappling to make a DC 17 Constitution saving throw as it absorbs blood through the creatures skin and into its wings. If the creature fails the save, they take 36 (8d8) necrotic damage on a failed save, or half as much damage on a successful one. If the creature fails their save by 5 or more, they also gain a point of exhaustion. If the targeted creature fails the Constitution save, the blood angel loses all levels of exhaustion it has and cures itself of being poisoned.