Vaedghest

Echolocation. The vaedghest has disadvantage on Wisdom (Perception) checks that rely on sight, and loses its Blindsight while deafened.

Kilter. The vaedghest has advantage on saving throws against effects that would cause it to be moved or knocked prone.

Legendary Resistance (1/Day). If the vaedghest fails a saving throw, it can choose to succeed instead.

Multiattack. The vaedghest makes two Bastard Sword attacks. It can use Give In in place of one Bastard Sword attack.

Bastard Sword. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 15 (2d8 + 6) slashing damage.

Give In. The vaedghest forces the hideous despair of its home plane upon a creature it can see within 60 ft. The creature must must make a DC 12 Wisdom saving throw or lose its self preservation instincts. Until the start of the vaedghest's next turn, the creature cannot add their Dexterity bonus to AC or saving throws, and all attack rolls that hit them are critical hits.

Negative Transit (3/Day). The vaedghest steps through the negative energy plane to teleport up to 1 mile to an unoccupied space that it can see, or has been to previously. If it has all uses of Negative Transit available, it can instead expend all uses tear open a portal between the negative energy plane and the prime material plane. The portal is wide enough for large or smaller creatures to pass through, and persists for 1 minute.

Sweep. The next time the vaedghest attacks a creature in melee range this turn, it can have the attack also target another creature in melee range adjacent to the first.

Riposte. When a creature misses the vaedghest with a melee weapon attack, the vaedghest may may a Bastard Sword attack against them if they are in range.

The vaedghest can take 2 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. The vaedghest regains spent legendary actions at the start of its turn.

Nightmarish Hierarchy. The vaedghest wills an allied aberration it can see to make an attack with their reaction.

Despair. The vaedghest uses its Give In action.

Dragging Charge (Costs 2 Actions). The vaedghest moves up to its speed in a straight line, and chooses to hold its weapon on its left or right side. Creatures in a 5 ft. line parallel to the vaedghest's movement must make a DC 18 Dexterity saving throw, taking 27 (6d8) slashing damage on a failed save.