Strahd von Zarovich, Master of Castle Ravenloft

Darklord Restoration. If Strahd dies, he revives with all his Hit Points in 1d10 weeks somewhere in Barovia.

Legendary Resistance (3/Day, or 4/Day in Lair). If Strahd fails a saving throw, he can choose to succeed instead.

Misty Escape. If Strahd drops to 0 Hit Points outside his resting place, he uses Shape-Shift to become mist (no action required). If he can’t use Shape-Shift, he is destroyed. While Strahd has 0 Hit Points in mist form, he can’t return to his vampire form, and he must reach his resting place within 2 hours or be destroyed. Once in his resting place, Strahd returns to his vampire form and has the Paralyzed condition until he regains any Hit Points, and he regains 1 Hit Point after spending 1 hour there.

Regeneration. Strahd regains 10 Hit Points at the start of his turn if he has at least 1 Hit Point and isn't in sunlight or running water. If Strahd takes Radiant damage or damage from holy water, this trait doesn't function at the start of his next turn.

Vampire Weakness. Strahd has these weaknesses:

Running Water. He takes 20 Acid damage if it ends its turn in running water.
Stake to the Heart. If a weapon that deals Piercing damage is driven into his heart while he has the Incapacitated condition in his resting place, he has the Paralyzed condition until the weapon is removed.
Sunlight. He takes 20 Radiant damage if he starts his turn in sunlight. While in sunlight, he has Disadvantage on attack rolls and ability checks.

Multiattack. Strahd makes two attacks, using Death Strike or Sickening Ray in any combination. He can replace one of these attacks with a use of (A) Bite or (B) Blighted Fire if available.

Death Strike (Vampire or Wolf Form Only). Melee Attack Roll: +10, reach 5 ft. Hit: 9 (1d8 + 5) Slashing damage plus 14 (4d6) Necrotic damage. If the target is a Large or smaller creature, it has the Grappled condition (escape DC 15) from one of two hands.

Sickening Ray. Ranged Attack Roll: +10, range 120 ft. Hit: 16 (2d10 + 5) Necrotic damage, and the target has the Poisoned condition until the start of Strahd's next turn.

Bite. (Bat or Vampire Form Only) Constitution Saving Throw: DC 19, one creature within 5 feet that is willing or that has the Grappled, Incapacitated, or Restrained condition. Failure: 21 (6d6) Necrotic damage. The target’s Hit Point maximum decreases by an amount equal to the half the damage taken, and Strahd regains Hit Points equal to that amount. A Humanoid reduced to 0 Hit Points by this damage rises the following night as a Vampire Spawn under Strahd's control, unless the Humanoid is restored to life or its body is destroyed.

Blighted Fire (Vampire Form Only) (Recharge 5–6). Dexterity Saving Throw: DC 19, all creatures within a 20 foot Sphere centered on a point Strahd can see within 90 feet. Failure: 14 (4d6) Fire damage and 14 (4d6) Necrotic damage. Success: Half damage.

Spellcasting. Strahd casts one of the following spells, using Intelligence as the spellcasting ability (spell save DC 19):

At Will: Detect Thoughts, Fog Cloud, Mage Hand, Prestidigitation, Sleep
2/Day Each: Animate Dead, Fly, Gust of Wind, Mirror Image, Nondetection
1/Day Each: Blight, Greater Invisibility, Polymorph, Scrying

Charm. Strahd casts Charm Person, requiring no spell components and using Charisma as the spellcasting ability (spell save DC 18). When the spell is cast this way, its duration is 24 hours, and the Charmed target is a willing recipient of Strahd's Bite, the damage of which doesn't end the spell. When the spell ends, the target is unaware it was Charmed by Strahd.

Shape-Shift. If Strahd isn’t in sunlight or running water, he shape-shifts into a Tiny bat (Speed 5 ft., Fly Speed 30 ft.), a Large wolf (Speed 40 ft.), or a Medium cloud of mist (Speed 5 ft., Fly Speed 20 ft. [hover]), or he returns to his vampire form. Anything it is wearing transforms with him.
While in bat or wolf form, Strahd can't speak. His game statistics, other than his size and Speed, are unchanged.
While in mist form, Strahd can’t take any actions, speak, or manipulate objects. He is weightless and can enter an enemy’s space and stop there. If air can pass through a space, Strahd can do so, but he can’t pass through liquid. Strahd has Resistance to all damage, except the damage he takes from sunlight.

Protective Magic (3/Day). Strahd casts Counterspell or Shield in reaction to that spell's trigger.

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature’s turn, Strahd can expend a use to take one of the following actions. Strahd regains all expended uses at the start of each of his turns.

Count's Command. Strahd casts Command (level 2 version), requiring no spell components and using Charisma as the spellcasting ability (spell save DC 18).

Striding Strike. Strahd moves up to half his Speed, and he makes one Death Strike or Sickening Ray attack.

Unhindered Movement. Strahd moves up to his Speed without provoking Opportunity Attacks. If he is in his lair, he can pass through solid walls, doors, ceilings, and floors as if they weren't there when he takes this action.