Regeneration. Vladimir regains 20 hit points at the start of its turn. If Vladimir takes cold or radiant damage, this trait doesn’t function at the start of his next turn. Vladimir's body is destroyed only if it starts its turn with 0 hit points and doesn’t regenerate.

Rejuvenation. When Vladimir's body is destroyed, its soul lingers. After 24 hours, the soul inhabits and animates another humanoid corpse on the same plane of existence and regains all its hit points. While the soul is bodiless, a wish spell can be used to force the soul to go to the afterlife and not return.

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

Vengeful Tracker. Vladimir knows the distance to and direction of any creature against which it seeks revenge, even if the creature and the revenant are on different planes of existence. If the creature being tracked by the revenant dies, the revenant knows.

Royal Pride. Vladimir makes Initiative rolls with advantage. If he rolls a 9 or lower, treat it as a 10. 

Aura of Hate.  When Vladimir drops below half health (150), his body sets ablaze. If an enemy ends it's turn within 10 feet of Vladimir, they must make a DC15 Wisdom save or take 9 (3d6) fire damage and be forced back 5ft. 

Soothing Cold. If Vladimir is struck by cold he must make a DC15 CON save. On a failure, Vladimir can only make 1 attack and cannot use his special attacks till the start of his next turn.

Multiattack. The revenant makes three Greatsword attacks. He can make one leaping slam during his second phase or a surging strike in place of two attacks. 

Greatsword. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 13 (4d6 + 6) bludgeoning damage. If the target is a creature against which the revenant has sworn vengeance, the target takes an extra 14 (4d6) bludgeoning damage. Instead of dealing damage, the revenant can grapple the target (escape DC 17) provided the target is Large or smaller. When Vladimir drops below half health, his body sets ablaze and he deals an additional 6 (2d6) fire damage on each attack. 

Leaping Slam.  Special Attack. Melee area of effect. Vladimir leaps up to 30 feet forward, raising his great sword up and slamming into the ground. Flames surge out in an 15ft radius sphere. Anyone within the range must make DC17 dexterity check or take 18 (6d6) fire damage and be knocked prone. 

Surging Strike. Special Attack. Melee Area of Effect. Vladimir adjusts his blade and surges forth in a 30ft line. Anyone affected must make a DC17 dexterity check or take (4d6 + 7) Slashing damage and have their movement speed dropped to 0. At the end of the next initiative count, his backtrail ignites and anyone on the line takes an extra (3d6) fire damage. The fire damages all who walk through it, and requires water or a gust to douse.

Vengeful Glare. Vladimir targets one creature it can see within 30 feet of it and against which it has sworn vengeance. The target must make a DC 15 Wisdom saving throw. On a failure, the target is paralyzed until the revenant deals damage to it, or until the end of the revenant’s next turn. When the paralysis ends, the target is frightened of the revenant for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, with disadvantage if it can see the revenant, ending the frightened condition on itself on a success.

Vladimir has 2 legendary actions per turn:

(Costs 1 action) Vladimir moves up to his movement without provoking attacks of opportunity

(Cost 1 actions) Vladimir makes a great sword attack

(Costs 2 actions) Vladimir makes a special attack.