Magic Resistance. Zulaqu has advantage on spells and magical effects..

Multi attack:  Zulaqu makes 2 attacks.  One with his crush organs and one with his mind blade

Mind Blast (recharge 2-6). Zulaqu psionically emits psychic energy in a 60-foot cone.  Each creature in that area must succeed on a DC 21 Intelligence saving throw or take 27 (4d8 +7) 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 itself on a success

Crush organs. Zulaqu targets one creature within 120 feet of himself.  Psionically, he crushes the internal organs of that creature.  The creature needs to succeed on a DC 21 Constitution saving throw or take 39 (8d8+7) bludgeoning damage if his psionic staff is in its pedestal.  If the staff is not in the pedestal then it only does 31 (6d8+7) bludgeoning damage.

Mind Blade. Melee weapon attack, +12 to hit, reach 5ft, one target, Hit: 11(1d8+7) or 12 (1d10+7) slashing damage if used with both hands.  It deals an additional 12 (3d6) psychic damage.

Enter the description for how bonus actions work for your monster here.

Psionic hold. Zulaqu stops an attacker coming to him with a melee attack strike, paralyzing them until the end of their next turn.  Similarly he can also do this with projectiles.

Zulaqu has 3 legendary actions in which he can use at the end of his or another creatures turn.

Psychic influence (3 actions). Zulaqu casts Dominate monster.

Psychic escape (2 actions). Zulaqu levitates 15 feet without provoking opportunity attacks.

Psionic shield ( 1 action). Until the end of Zulaqu's next turn Zulaqu makes a psychic force field that gives him 15 temporary hitpoints.

Villain actions are used on a certain round in combat.

Heart Attack (round 1). Zulaqu reaches out his hand and a creature within 120 feet of him must succeed on a DC 21 Constitution Saving throw or fall to 0 hitpoints and needs to make death saving throws.

Psychic Explosion (round 3). If the pedestal still holds Zulaqu's psionic staff it erupts and sends a shockwave of psychic energy causing all creatures within 120 feet of Zulaqu to need to make a DC 21 Intelligence saving throw.  On a failed save the creature takes 48 (8d12) Psychic damage and are pushed 60 feet away from Zulaqu and fall prone.  On a success, creatures take half damage and are not knocked prone