Multiattack.The corrupter makes three Whispering Blade attacks and can use Debilitating Touch.
Whispering Blade.mw,rw 12 to hit, reach 5 ft. or range 60 ft., one target. ({@damage 1d8 + 6) piercing damage plus 14 (4d6) psychic damage. If the target is a creature, it must succeed on a 20 Wisdom saving throw or be unable to speak until the start of the corrupter's next turn.
Debilitating Touch.The corrupter's squirming tentacle lashes out at a creature the corrupter can see within 30 feet of itself. The target must succeed on a 20 Constitution saving throw or have the paralyzed condition until the end of its next turn, after which the target is immune to this Debilitating Touch for 24 hours.
Legendary Actions.The creature can take 3 legendary actions...
Cunning.The corrupter escapes nonmagical restraints and ends the grappled and restrained conditions on itself, then moves up to its speed without provoking opportunity attacks.
Stab (Costs 2 Actions).The corrupter makes one Whispering Blade attack.
Amorphous Escape (Costs 3 Actions).The corrupter dissolves into a shifting mass of flesh, tentacles, eyes, claws, and mouths. Up to two creatures the corrupter can see within 20 feet of itself must make a 20 Intelligence saving throw, taking 18 (4d8) psychic damage on a failed save, or half as much damage on a successful one. This transformation lasts until the end of the corrupter's next turn. While transformed, the corrupter has advantage on attack rolls, attack rolls made against it have disadvantage, and it can move through spaces at least 1 inch wide without squeezing.
Reactions.Reactions the creature can take:
Uncanny Dodge.When an attacker the corrupter can see hits the corrupter with an attack, the corrupter halves the attack's damage against it.