Rejuvenation. If it has a phylactery, Zavad gains a new body in 1d10 days, regaining all its hit points and becoming active again. The new body appears within 5 feet of the phylactery.

Unusual Nature. Zavad doesn't require air, food, drink, or sleep.

Ventriloquism. Whenever Zavad speaks, he can choose a point within 60 feet of him; his voice emanates from that point.

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

Evasion. If Zavad is subjected to an effect that allows it to make a saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Legendary Resistance (3/Day). If Zavad fails a saving throw, it can choose to succeed instead. 

Turn Immunity. Zavad is immune to effects that turn undead.

Devil Sight. Zavad can see normally in darkness, both magical and nonmagical, to a distance of 120 feet.

Spellcasting. Zavad casts one of the following spells, requiring no material components and using Charisma as the spell casting ability (spell save DC 23):
At will: dissonant whispers, mind spike, alter self, darkness, major image, sending
3/day each: greater invisibilty, psychic lance
1/day each: synaptic static

Multiattack. Zavad makes two Stealth Claw attacks.

Stealth Claw. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 20 (3dl0 + 4) piercing damage plus 22 (4dl0) necrotic damage.

Teleport. Zavad teleports, along with any equipment he is wearing or carrying, up to 120 feet to an unoccupied space he can see.

Twisting Words. Zavad targets one creature he can see within 60 feet of him. The target must succeed on a DC 23 Charisma saving throw or become charmed by Zavad for l minute. The charmed target can repeat the saving throw if Zavad deals any damage to it. A creature that succeeds on the saving throw is immune to Zavad's Twisting Words for 24 hours.

Frightful Word. Zavad targets one creature he can see within 10 feet of him. The target must succeed on a DC 23 Wisdom saving throw or become frightened of him for l minute. While frightened in this way, the target must take the Dash action and move away from Zavad by the safest available route on each of its turns, unless there is nowhere to move, in which case it needn't take the Dash action. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Shadow Stealth. While in dim light or darkness, Zavad takes the Hide action.

Deadly Reach. In response to a creature entering a space within 15 feet of it, Zavad makes one Stealth Claw attack against that creature.

Zavad can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Zavad regains spent legendary actions at the start of his turn.

Corrupting Guidance. Zavad uses Twisting Words. Alternatively, he targets one creature charmed by him that is within 60 feet of him; that charmed target must succeed on a DC 23 Charisma saving throw, or Zavad decides how the target acts during its next turn.
Teleport. Zavad uses Teleport.
Assault (Costs 2 Actions). Zavad makes one Stealth Claw at tack, or he uses Frightful Word.