Creename

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

Innate Spellcasting (Psionics). The creename's innate spellcasting ability is Intelligence (spell save DC 15). It can cast the following spells at will, requiring no components:
At will: mage hand (the hand is invisible), detect thoughts, levitate 
1/day each: dominate monster, plane shift (self only) 

Multiattack. The creename makes two mind blast attacks, or a bite and control mind attack.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 6 (1d12 + 0) piercing damage. If the target is Medium or smaller, it must succeed on a DC 15 Intelligence saving throw or be grappled by the creename. A creature grappled in this way is stunned, and the grapple ends if the stunned effect is removed. The creename can have only one creature grappled in this way.

Control Mind. Melee Weapon Attack: +7 to hit, reach 5 ft., one incapacitated humanoid grappled by the creename. Hit: 12 (2d8 + 4) psychic damage. If this damage reduces the target to 0 hit points, the creename kills the target by devouring its brain and replacing it. If this happens, the creename is replaced with the target, who has full health and is changed accordingly: Its spells (if any) are replaced with the creename's Innate Spellcasting (Psionics) trait, its Intelligence, Wisdom, and Charisma scores are replaced by the creename's, knows only the creename's languages, its proficiency are replaced with the creename's, and has the Mind Blast action and the following action, Leave Host. The humanoid dies and in its place is a creename.

Mind Blast (Recharge 6). The creename magically emits psychic energy in a 30-foot cone. Each creature in that area must succeed on a DC 15 Intelligence saving throw or take 16 (4d6 + 4) psychic damage and be stunned for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on a success.