Alienist

Alien Mind. If a creature tries to read the alienist’s thoughts or deals psychic damage to it, that creature must succeed on a DC 15 Intelligence saving throw or be stunned for 1 minute. The stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Multiattack. The alienist makes three Eldritch Burst attacks.

Eldritch Burst. Melee or Ranged Spell Attack: +7 to hit, reach 5 ft. or range 120 ft., one target. Hit: 20 (3d10 + 4) psychic damage.

Spellcasting. The alienist casts one of the following spells, using Intelligence as the spellcasting ability (spell save DC 15):

At will: arms of Hadar, detect thoughts, mage armor
3/day each: banishment, dimension door, Evard's black tentacles, hunger of Hadar, magic circle (as an action), summon aberration (6th-level version)
1/day each: gate, reality break, symbol (as an action)