Bordello of Blood

Evasion. If she is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, she instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

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

She is an 5th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 16, +5 to hit with spell attacks). She can cast disguise self and invisibility at will and has the following wizard spells prepared:

Cantrips (at will): fire bolt, light, mage hand, prestidigitation, shocking grasp.

1st level (4 slots): charm person, color spray, mage armor*, magic missile

2nd level (3 slots): detect thoughts, mirror image, misty step

3rd level (2 slots): counterspell, lightning bolt

 *She casts these spells on itself before combat.

Legendary Resistance (3/Day). If the she fails a saving throw, she 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 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 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.

While it has 0 hit points in 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.

Regeneration. She regains 20 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, this trait doesn’t function at the start of the vampire’s next turn.

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.

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

Claws (Vampire Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 8 (1d4+4) slashing damage. Instead of dealing damage, She can grapple the target (escape DC 18).

Kiss of Death. (Vampire Form Only). Melee Weapon Attack: +9 to hit, reach 5 ft., one willing creature, or a creature that is grappled by the vampire, incapacitated, or restrained. Hit: 7 (1d6 +4) nercotic damage plus 5 (3d6) necrotic damage.

The target’s hit point maximum is reduced by an amount equal to the necrotic damage taken, and she regains hit points equal to that amount by feeding on their life energy. 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. She targets one humanoid it can see within 30 feet of it. If the target can see her, the target must succeed on a DC 17 Wisdom saving throw against this magic or be charmed by her. 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 her kiss. This charm can only effect male humanoids because she will not feed on females life energy, she is cursed never to harm another female by the goddess Tymora.

Each time her or her 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.

She 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. She regains spent legendary actions at the start of its turn.

Flyby. She doesn't provoke opportunity attacks when she flies out of an enemy's reach.

Claws. She can makes one claw attack.

Kiss of Death (Costs 2 Actions). The vampire makes one kiss attack.