Assassin Revenant

Evasion. If the Assassin Revenant is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, the Assassin Revenant instead takes no damage if it succeeds on the save and only half damage if it fails. It can’t use this trait if it has the Incapacitated condition.

Regeneration. The Assassin Revenant regains 10 Hit Points at the start of each of its turns. If the Assassin Revenant takes Fire or Radiant damage, this trait doesn’t function at the start of its next turn. Its body is destroyed only if it starts its turn with 0 Hit Points and doesn’t regenerate.

Undead Restoration. If the Assassin Revenant dies, it revives 24 hours later in a different body unless Dispel Evil and Good is cast on its corpse. A Wish spell or divine intervention can also force the Assassin Revenant to move on to the afterlife. If it revives, it animates a Humanoid corpse elsewhere on the same plane of existence; it now looks different but uses the same stat block and returns with all its Hit Points.

Turn Immunity. The revenant is immune to effects that turn undead.

Multiattack. The Assassin Revenant uses Vengeful Glare and makes two Assassin's Blade attacks.

Assassin's Blade. Melee or Ranged Attack Roll: +7, reach 5 ft. or range 20/60 ft. Hit: 11 (2d6 + 4) Piercing damage.

If the target is cursed by the Assassin Revenant (see Vow of Revenge), the target takes an extra 14 (4d6) Necrotic damage.

Once per turn, if the Assassin Revenant has advantage on a roll and hits, the target takes an additional 14 (4d6) Piercing damage.

Vengeful Glare. Wisdom Saving Throw: DC 15, one creature the Assassin Revenant can see within 30 feet. Failure: The target has the Frightened condition and repeats the save at the end of each of its turns, ending the effect on itself on a success. After 1 minute, it succeeds automatically. If the Frightened target is cursed by the Assassin Revenant (see Vow of Revenge), the target also has the Paralyzed condition for the duration or until the Assassin Revenant causes damage to the target. 

Cunning Action. The Assassin Revenant takes the Dash, Disengage, or Hide action.

Vow of Revenge (1/Day). The Assassin Revenant curses one creature it can see within 30 feet of itself. The Assassin Revenant knows the distance to and direction of the cursed target, even if it is on a different plane of existence. The curse ends on the target if the revenant uses this Bonus Action on a different creature. If the creature cursed by the Assassin Revenant dies, the Assassin Revenant knows.

Uncanny Dodge. When an attacker the Assassin Revenant can see hits the Assassin Revenant with an attack, the Assassin Revenant halves the attack’s damage against it.

The revenant assassin 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. The assassin regains all spent legendary actions at the start of its turn.

Legendary Resistance Action (2/Day) (costs 1 action). The revenant assassin can instantly end one ongoing effect that comes from one saving throw they have previously failed.

Cunning. The revenant assassin escapes nonmagical restraints and ends the grappled condition on itself, then moves up to its speed without provoking opportunity attacks.

Stab (Costs 2 Actions). The revenant assassin makes one Assassin's Blade attack.