Marshal Undead. Unless the Fright Knight is incapacitated, it and any undead creatures of its choice within 60 feet of it have advantage of saving throws against features that turn undead.

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

Mauler of Minds. When Fright Knight scores a critical hit with Soulreaver, the target must make a Wisdom saving throw (DC 16). On a failure, the target sees phantasmal manifestations of their worst nightmares. While the target is affected, they are Frightened and suffer 4d10 psychic damage at the end of each of their turns. The target may make another Wisdom saving throw at the beginning of each of their turns to end the effect.

Dread Legion. Whenever Soulreaver is used to reduce a creature to 0 hit points by either a critical hit, or the damage from Mauler of Minds, that creature rises as a zombie under Fright Knight's control 1d4 turns later, as if by the animate dead spell. It may renew or dismiss any number of zombies raised in this way as a bonus action.

Fright Knight Weakness. The Fright Knight has the following flaw:

Bound to Blade. The Fright Knight cannot be greater than 5 feet away from his sword, Soulreaver, for more than 24 hours without losing control of its host.

Actions

Multiattack. The Fright Knight makes three attacks with Soulreaver.

Soulreaver. Melee Weapon Attack: +10 to hit, reach 5ft., one target. Hit 12 (1d8 + 8) slashing damage, or 13 (1d10 + 8) slashing damage if used with two hands, plus 6 (1d12) psychic damage.

Hellfire Orb (Recharge 5-6) The Fright Knight hurls a magical ball of purple fire that explodes at a point it can see within 120 feet of it. Each creature in a 20-foot-radius sphere centered on that point must make a DC 18 Dexterity saving throw. The sphere spreads around corners. A creature takes 35 (10d6) fire damage and 35 (10d6) necrotic damage on a failed save, or half as much damage on a successful one.

Legendary Actions

The Fright Knight can take 3 legendary actions. Only one legendary action option can be used at a time and only at the end of another creature's turn. The Fright Knight regains spent legendary actions at the start of its turn.

Move. Fright Knight can move up to half its speed without provoking opportunity attacks.

Soulreaver. Fright Knight makes one attack with Soulreaver

Reactions

Parry. The Fright Knight adds 6 to its AC against one melee attack that would hit it. To do so, it must see the attacker and be wielding a melee weapon.