Angel of Decay

Festering Presence. If the angel has at least 105 HP, a creature that starts its turn within 15 feet of it must succeed on a DC 17 Constitution saving throw or be infected with Festering Necrosis.

Parasitic Presence. If the angel has at least 105 HP or fewer, it regains 10 hit points at the beginning of its turn for each corpse and each creature within 60 feet infected with Festering Necrosis.

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

Festering Necrosis. An infected creature gains vulnerability to necrotic damage. Whenever an infected creature would vail one death save, it instead fails two death saves.

Multiattack. The angel makes two melee attacks, one of which it may replace with its foul unraveling, if available.

Rotting Touch. Melee Weapon Attack: +11 to hit, reach 15 ft., on target. Hit: 9 (1d6+6) slashing damage plus 18 (4d8) necrotic damage. This attack scores a critical on 16-20 against a creature with fewer than 100 hit points.

Foul Unraveling.The angel lashes out with tendrils of vile corruption, making a rotting touch attack against each creature within 15 feet. On a hit, a creature is dragged up to 10 feet towards the angel and greappled (escape DC 17) and restrained until the end of the angel's turn.

Wave of Decay. As a reaction to being reduced below 105 hit points, the angel unleashes a wave of negative energy. Each creature within 30 feet must succeed on a DC 17 Constitution saving throw or tak 27 (6d8) necrotic damage, or half as much on a success.