Shapechanger. If the vampire isn't in sunlight or running water, it can use its action to polymorph in to a Tiny bat, a Large giant bat, or a Medium cloud of blood-mist, or back into its true form. While in bat or giant 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 blood-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 blood-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. While the blood-mist isn't in sunlight, any creature that touches it or hits it with a melee attack while within 5 feet of it takes 13 (3d8) acid damage plus 10 (3d6) necrotic damage.

Blood Form (Mythic Trait; Recharges after a Short or Long Rest). If the vampire is reduced to 0 hit points, it may use this ability. It doesn't die, fall unconscious, or use its Misty Escape trait. Instead, the vampire's body turns inside out and transforms entirely into blood, and the vampire regains 180 hit points. Each creature that has blood within 120 feet of the vampire must succeed on a DC 21 Constitution saving throw or take 27 (5d10) necrotic damage. For the next 1 hour, the vampire is immune to necrotic damage unless it is dealt by a Blood spell, and it can't be grappled or restrained.

Bloodsight. The vampire's blindsight extends through total cover, but it can't perceive creatures that don't have blood, and it can't perceive any objects other than blood. A thin sheet of lead or adamantine can block this blindsight. In addition, it can magically sense the presence of living creatures that have blood up to 5 miles away. It knows the general direction they're in but not their exact locations.

Draining Claws. Each creature of the vampire's choice that is grappled by the vampire takes 9 (2d8) necrotic damage at the start of each of the vampire's turns. While the vampire's Blood Form trait is active, this damage is doubled.

Greater Regeneration. The vampire regains 30 hit points at the start of its turn if it has at least 1 hit point and isn't in sunlight or running water. If the vampire takes radiant damage or damage from holy water, it only regains 10 hit points at the start of its next turn.

Hematurgy. As a bonus action, the vampire can expend up to 25 hit points or blood points. The next spell it casts on that turn with a spell level of no more than the amount of expended points divided by five is a Blood spell and doesn't expend a spell slot.

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

Misty Escape. When it drops to 0 hit points outside its resting place, the vampire transforms into a cloud of blood-mist (as in the Shapechanger trait) instead of falling unconscious, provided that it isn’t in sunlight or running water. If it can’t transform, it is destroyed.

While it has 0 hit points in blood-mist form, it can’t revert to its vampire form, and it must reach its resting place within 2 hours or be destroyed. Once in its resting place, it reverts to its vampire form. It is then paralyzed until it regains at least 1 hit point. After spending 1 hour in its resting place with 0 hit points, it regains 1 hit point.

Spellcasting. The vampire is a 25th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 22, +14 to hit with spell attacks). It knows the following spells as sorcerer spells:

Cantrips (at-will): blade ward, blood boil (new), dancing lights, friends, gore spike (new), hemokinesis (new), spare the dying
1st level (4 slots): blood reading (new), disguise self, sleep
2nd level (3 slots): carnage burst (new), invisibility
3rd level (3 slots): clairvoyance, major image
4th level (3 slots): dimension door, dominate beast
5th level (3 slots): dominate person, hold monster
6th level (3 slots): circle of death, eyebite
7th level (3 slots): finger of death, plane shift
8th level (3 slots): dominate monster, heart break (new)
9th level (2 slots): power word kill, rizzak's red death (new)

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

Turn Resistance. The vampire has advantage on saving throws against any effect that turns undead.

Vampire Weaknesses. The vampire has the following flaws:

Forbiddance. The vampire can’t enter a residence without an invitation from one of the occupants.

Harmed by Running Water. The vampire takes 20 acid damage if it ends its turn in running water.

Stake to the Heart. If a piercing weapon made of wood is driven into the vampire’s heart while the vampire is incapacitated in its resting place, the vampire is paralyzed until the stake is removed.

Sunlight Hypersensitivity. The vampire takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks.

Vampiric Blood Magic. When the vampire deals necrotic damage to a creature that has blood using its Unarmed Strike, Bite, Draining Claws, or a Blood spell, it gains a number of blood points equal to half of the damage dealt, and the creature must succeed on a DC 21 Constitution saving throw or be poisoned until the end of its next turn. The vampire can't ever have more than 100 blood points.

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

Unarmed Strike (Vampire Form Only). Melee Weapon Attack: +12 to hit, reach 5 ft., one creature. Hit: 10 (1d8 + 6) bludgeoning damage plus 9 (2d8) necrotic damage. Instead of dealing damage, the vampire can grapple the target (escape DC 21).

Bite (Bat, Giant Bat, or Vampire Form Only). Melee Weapon Attack: +12 to hit, reach 5 ft., one willing creature, or a creature that is grappled by the vampire, incapacitated, or restrained. Hit: 9 (1d6 + 6) piercing damage plus 27 (8d6) 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.

Charm. The vampire targets one humanoid it can see within 30 feet of it. If the target can see the vampire, the target must succeed on a DC 20 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's bite attack.
    Each time the vampire or the vampire's 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. The vampire magically calls 2d4 swarms of bats or rats, provided that the sun isn’t up. While outdoors, the vampire can call 3d6 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 dies, or until the vampire dismisses them as a bonus action.

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.

Unarmed Strike. The vampire makes one unarmed strike.

Bite (Costs 2 Actions). The vampire makes a bite attack.

Blood Sorcery (Costs 2 Actions). The vampire casts a spell of 5th-level or lower that normally requires an action or bonus action to cast.

Unholy Call (Costs 2 Actions). The vampire uses its Children of the Night action.

If the vampire's mythic trait is active, it can use the options below as legendary actions for 1 hour after using its Blood Form trait.

Blood Lash. The vampire makes two unarmed strikes against different targets. Each attack has a reach of 15 feet and if the vampire grapples a target, it also pulls the target up to 10 feet closer to it.

Transfuse. The vampire makes one bite attack with advantage. It deals 14 (4d6) extra necrotic damage on a hit.

Surge (Costs 2 Actions). The vampire moves up to twice its speed without provoking opportunity attacks. It can enter an enemy's space, but it can't end this movement there. Whenever the vampire enters a creature's space for the first time on a turn during this movement, it can make an unarmed strike attack against that creature. It can't use these attacks to grapple.