Shapechanger. If the vampire isn’t in sunlight or running water, it can use its action to polymorph into a Tiny bat or a Medium cloud of mist, or back into its true form.

While in bat form, the vampire can’t speak, its walking speed is 5 feet, and it has a flying speed of 30 feet. Its statistics, other than its size and speed, are unchanged. Anything it is wearing transforms with it, but nothing it is carrying does. It reverts to its true form if it dies.

While in mist form, the vampire can’t take any actions, speak, or manipulate objects. It is weightless, has a flying speed of 20 feet, can hover, and can enter a hostile creature’s space and stop there. In addition, if air can pass through a space, the mist can do so without squeezing, and it can’t pass through water. It has advantage on Strength, Dexterity, and Constitution saving throws, and it is immune to all nonmagical damage, except the damage it takes from sunlight.

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

Misty Escape.  When the vampire drops to 0 hit points outside of its resting place, the vampire lord transforms into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious, provided that is isn't in sunlight or running water. If it can't transform, it is destroyed. Once in its resting place, it reverts to its vampire form. It is then forced to remain in its resting place until it regains at least 1 hit point. After spending 1 minute in its resting place with 0 hit points, it regains 1 hit point.

Regeneration. The vampire lord regains 30 hit points at the start of its turn if it has at least 1 hit point and isn't in sunlight. If the vampire takes radiant damage or damage from holy water, this trait doesn't function at the start of the vampire lord's next turn.

Spider Climb. The vampire lord can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Death Warden. When casting the animate dead or create undead spell, there is no limit to how many creatures the vampire can have under its control. In addition, after casting animate dead or create undead once on creatures, it no longer needs to be cast on those creatures to retain its control over them.

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

Marshal Undead. Undead creatures within 60 feet of the vampire have advantage on saving throws against effects that turn undead.

Magic Resistance. The vampire has advantage on saving throws against spells and other magical effects.

Enhanced Attacks. The vampire's unarmed strike and vampiric touch attacks are treated as magical for the purpose of overcoming resistance and immunity to nonmagical damage.

Innate Spellcasting. The vampire's innate spellcasting ability is Charisma (spell save DC 23, +15 to hit with spell attacks). The vampire can innately cast the following spells requiring no material components:

At will: animate dead, blight, chill touch, darkness, disguise self, greater invisibility, levitate, telekinesis
5/day each: create undead, eyebite, dominate person, fear
3/day each: finger of death, circle of death (cast using a 7th level spell slot), waves of exhaustion
1/day each: dominate monster (cast using a 9th level spell slot), power word kill

Frightful Presence. Each creature of the vampire lord's choice that is within 120 feet of the vampire lord must succeed on a DC 22 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the vampire lord's Frightful Presence for the next 24 hours.

Multiattack (Humanoid or Vampire Form Only). The vampire makes three attacks, only one of which can be a bite attack.

Unarmed Strike (Humanoid or Vampire Form Only). Melee Weapon Attack: +14 to hit, reach 5 ft. (10 ft. in vampire form), one creature. Hit: 11 (1d10 + 6) bludgeoning damage. Instead of dealing damage, the vampire can grapple the target (escape DC 22).

Vampiric Touch (Vampire Form Only). Melee Spell Attack: +15 to hit, reach 10 ft., one creature. Hit: 28 (6d6 + 7) necrotic damage. The vampire regains hit points equal to half the necrotic damage dealt. In addition, if the target is a creature that is Medium or smaller, the target is grappled (escape DC 22). The vampire lord can continue to use the Vampiric Touch action on a grappled creature once a turn. A humanoid slain by this attack rises as a zombie after 1 hour under the vampire's control. The vampire cannot use this action when it is in direct sunlight.

Bite (Bat or Vampire Form Only). Melee Weapon Attack: +14 to hit, reach 5 ft., one willing creature, or a creature that is grappled by the vampire, incapacitated, or restrained. Hit: 16 (3d6 + 6) piercing damage plus 21 (6d6) necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and the vampire regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under the vampire's control.

Soul Drain (Vampire Form Only; Recharge 5-6). Ranged Spell Attack: +15 to hit, range 60 ft., one creature. Hit: 42 (10d6 + 7) necrotic damage. The target makes a DC 23 Constitution saving throw or the vampire regains hit points equal to the necrotic damage dealt. In addition, if the target fails the Constitution saving throw, the target's hit point maximum is reduced by the amount of damage dealt. If the hit points gained restores the vampire lord to its hit point maximum, it gains the excess as temporary hit points. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under the vampire's control. The vampire cannot use this action when it is in direct sunlight.

Charm. The vampire targets one humanoid it can see within 30 feet of it. If the target can see the vampire lord, the target must succeed on a DC 23 Wisdom saving throw against this magic or be charmed by the vampire. The charmed target regards the vampire as a trusted friend to be heeded and protected. Although the target isn't under the vampire's control, it takes the vampire's requests or actions in the most favorable way it can, and it is a willing target for the vampire lord's bite attack. Each time the vampire or its companions do anything harmful to the target, it can repeat the saving throw, ending the effect on itself on a success. Otherwise, the effect lasts 24 hours or until the vampire is destroyed, is on a different plane of existence than the target, or takes a bonus action to end the effect

Children of the Night (3/Day). The vampire magically calls 4d6 giant bats or rats, provided that the sun isn't up. While outdoors, the vampire can call 3d6 dire wolves instead. The called creatures arrive in 1d4 rounds, acting as allies of the vampire and obeying its spoken commands. The beasts remain for 1 hour, until the vampire lord dies, or until the vampire lord dismisses them as a bonus action.

Poise. The vampire uses its reaction to avoid damage from a melee or ranged weapon attack.

The vampire 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 vampire regains spent legendary actions at the start of its turn.

Move. The vampire moves up to its speed without provoking opportunity attacks.
Vampiric Touch or Unarmed Strike. The vampire makes one Vampiric Touch attack or one unarmed strike.
Bite (Costs 2 Actions). The vampire makes one bite attack.
Cast a Spell (Costs 2 Actions). The vampire casts a spell from its Innate Spellcasting feature, expending a use of that spell as normal.
Absorb Life (Costs 3 Actions). Every non-undead creature within a 30-foot radius of the vampire lord must make a DC 23 Dexterity saving throw. On a failed save, creatures take 35 (10d6) necrotic damage and have their hit point maximum reduced by that amount until the greater restoration spell or similar magic is cast on them. On success, creature take half damage and do not have their hit point maximum reduced. The vampire regains the amount of necrotic damage dealt as hit points. If the amount of hit points the vampire gains restores the vampire to its hit point maximum, the vampire lord gains the excess as temporary hit points. A humanoid slain in this way becomes a wraith under the vampire's control. The vampire cannot use this action when it is in direct sunlight.