Regeneration. The vampire regains 10 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.

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

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 when it ends its turn in running water.

Stake to the Heart. The vampire is destroyed if a piercing weapon made of wood is driven into its heart while it is incapacitated in its resting place.

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.

Bride’s Trickery (Once Per day): When Volenta is below half health of her maximum health,  This effect ends in 10 minutes. Any charmed creature is under Volenta’s complete control, and as a bonus action she can issue a command to any charmed creature that can hear her. When a hostile creature or charmed creature moves to a space next to her, she can use her reaction to vanish in mist form and reappear at a point she can see within 30 feet of her.

Legendary Resistance (Once a day): If she fails a saving throw she can choose to succeed instead.

Multiattack. The vampire makes two attacks, only one of which can be a bite attack.

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 8 (2d4 + 3) slashing damage. Instead of dealing damage, the vampire can grapple the target (escape DC 13).

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one willing creature, or a creature that is grappled by the vampire, incapacitated, or restrained. Hit: 6 (1d6 + 3) piercing damage plus 7 (2d6) 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.

+1 Rapier. Melee Weapon Attack: +9 to hit, react 5 ft., one creature. Hit: (1d8 + 3) piercing damage. If she has advantage on the attack roll or another alley is within 5 feet of the target, the attack deals an additional (3d8) damage once per turn. 

Charm. Volenta targets one humanoid she can see within 30 feet of her. If the target can see the Volenta, the target must succeed on a DC 16 Wisdom saving throw against this magic or be charmed by her. The charmed target regards Volenta as a trusted friend to be heeded and protected. Although the target isn’t under Volenta’s control, it takes her requests or actions in the most favorable way it can, and it is a willing target for the vampire’s bite attack.

Each time Volenta 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 Volenta takes a bonus action to end the effect.

Elusive. Brides Trickery must be active to use this reaction. When a hostile creature or charmed creature moves to a space next to her, she can use her reaction to vanish in mist form and reappear at a point she can see within 30 feet of her.

Parry. Volenta can use her reaction to add +3 to her armor class if she is wielding a finesse weapon.