Vanil'ewia

Horde of Nine. The Vanil'ewia can control up to nine creatures of its choosing.  Physical touch to its head results in the attacker making a DC 18 WIS Save.  On a failed save, the attacker comes under the control of the Vanil'ewia.  (This is similar to the Borg collective's Hive Mind ability.)  At the start of the controlled entity's turn, they make repeat the WIS Save, and on a success they are immune to the mind control for one hour. 

Double Trouble. The Vanil'ewia can take four actions a turn.  

Staff of Domination. Melee Weapon Attack: +11 to hit, reach 5 ft., 1 target. Hit: 16 (2d8 + 5) bludgeoning damage. 

Pierce the Soul. Ranged Weapon Attack: +11 to hit, range 30/200 ft., 1 target. Hit: 10 (4d4 + 3) psychic damage.

Try Again. Once per round, the Vanil'ewia can stare at an opponent and force disadvantage after being declared as the target of an attack.

End of Time (Costs 3 Actions). From where the Vanil'ewia currently is located, a wave of necrotic energy radiates out, striking all enemies within a 200 ft radius.  All enemies must succeed on a DEX Saving Throw (DC 22) or take 10 d6 necrotic damage.   On a failed save, they take half damage.