Succubus Form. When The Caller finishes a Long Rest, he can shape-shift into a Succubus, using that stat block instead of this one. Any equipment he's wearing or carrying isn’t transformed.

Telepathic Bond. The Caller ignores the range restriction on his telepathy when communicating with a creature he has charmed. The two don't even need to be on the same plane of existence.

Spellcasting. The Caller casts one of the following spells, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 16):

At Will: Disguise Self
1/Day each: Fireball, Hypnotic Pattern

Multiattack. The Caller makes two Claw attacks.

Claw (Fiend Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) slashing damage.

Draining Kiss. The Caller kisses a creature charmed by him or a willing creature. The target must make a DC 16 Constitution saving throw against this magic, taking 32 (5d10 + 5) psychic damage on a failed save, or half as much damage on a successful one. The target's hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Etherealness. The Caller magically enters the Ethereal Plane from the Material Plane, or vice versa.

Shapechanger. The Caller polymorphs into a Small or Medium humanoid, or back into his true form. Without wings, The Caller loses his flying speed. Other than his size and speed, his statistics are the same in each form. Any equipment he is wearing or carrying isn't transformed. He reverts to his true form if he dies.

Charm. One humanoid The Caller can see within 30 feet of him must succeed on a DC 16 Wisdom saving throw or be magically charmed for 1 day. The charmed target obeys The Caller's verbal or telepathic commands. If the target suffers any harm or receives a suicidal command, it can repeat the saving throw, ending the effect on a success. If the target successfully saves against the effect, or if the effect on it ends, the target is immune to The Caller's Charm for the next 24 hours.

The Caller can have only one target charmed at a time. If he charms another, the effect on the previous target ends.