Calliope

 Innate Spellcasting. Calliope spellcasting ability is Charisma (spell save DC 21). It can innately cast the following spells, requiring no material components:

2/day each: confusion (*30 ft. sphere), crown of madness

1/day: power word pain

Legendary Resistance (3/Day). If Calliope fails a saving throw, she can choose to succeed instead.

Spiderclimb. Calliope has a climb speed of 40. 

Sunlight Hypersensitivity. While in sunlight, Calliope takes 20 radiant damage at the start of her turn, and she has disadvantage on attack rolls and ability checks.

Multiattack. Calliope makes three attacks, only one of which can be a bite attack. 

Bite. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 9 (1d6+ 8) piercing damage plus 14 (4d6) necrotic damage. The target’s hit point maximum is reduced by an amount equal to the necrotic damage taken and Calliope regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if its hit point maximum is reduced to 0.

Claws. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 17 (2d8 + 8) slashing damage plus 14 (4d6) necrotic damage. 

Piercing Scream. Calliope unleashes a blood-curdling scream in a 30 foot cone. Each creature in that area must succeed on a DC 19 Wisdom saving throw, taking 36 (8d8) psychic damage on a failed save, or half as much damage on a successful one. On a failed save the creature becomes deafened for one minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Misty Step. Calliope can misty step at will as a reaction. 

Calliope 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. Calliope regains spent legendary actions at the start of his turn.

Claws. Calliope makes one claw attack.

Bite (Costs 2 Actions). Calliope makes one bite attack.

Piercing Scream (Costs 3 Actions). Calliope makes one piercing scream.