Coilldeen

Detect Life. The coilldeen can magically sense the presence of creatures up to 5 miles away that aren’t undead or constructs. She knows the general direction they’re in but not their exact locations.

Incorporeal Movement. The coilldeen can move through other creatures and objects as if they were difficult terrain. She takes 5 (1d10) force damage if she ends her turn inside an object.

Consume Life. Whenever the coilldeen damages a non-undead creature, she consumes an amount of HP equal to half the damage dealt. If the damage dealt brings a creature to 0 HP (Including with her Wail ability) she consumes an amount of HP equal to the full amount of the damage dealt.  Once the coilldeen has consumed a total amount of HP equal to her Max HP she becomes corporeal (see secondary stat block for new stats/abilities) and is at max HP for her new form.

Corrupting Touch. Melee Spell Attack: +5 to hit, reach 5 ft., one target. Hit: 12 (3d6 + 3) necrotic damage.

Siren Song. Each non-undead creature within 60 feet of the coilldeen that can hear her must succeed on a DC 14 Wisdom saving throw or be charmed for 1 minute.  A creature charmed in this way must use all of its movement to move towards the coilldeen and is otherwise incapacitated. A charmed target can repeat the saving throw at the end of each of its turns, with disadvantage if the coilldeen is within line of sight, ending the effect on itself on a success. If a target’s saving throw is successful or the effect ends for it, the target is immune to the coilldeen’s Siren Song for the next 24 hours.

Wail (1/Day). The coilldeen releases a mournful wail, provided that she isn’t in sunlight. This wail has no effect on constructs and undead. All other creatures within 30 feet of her that can hear her must make a DC 14 Constitution saving throw. On a failure, a creature drops to 0 hit points. On a success, a creature takes 10 (3d6) psychic damage.

Corrupting Touch. If a creature affected by the coilldeen's Siren Song moves into her melee range (5 ft) she can use Corrupting Touch as a reaction. Melee Spell Attack: +5 to hit, reach 5 ft., one target. Hit: 12 (3d6 + 3) necrotic damage.