Regeneration. Volenta 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. Volenta can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Prostitute's Charm. As an action, Volenta can use her seduction skills from her previous life to her advantage. She can target one Humanoid she can see within 30 ft. If the target can see Volenta and is normally attracted by females, the target must succeed a DC16 Wisdom saving throw or be charmed. The Charmed target regards Volenta 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 bit Attack. 
Each time the vampire or the vampire's companions do anything harmful to the target, or the vampire targets someone else, the effect ends. Otherwise he effect lasts until the character takes a short/long rest or 4 hours, whichever comes first.

Animal Control. Once a day, Volenta can summon 1d4 Dire Wolves to do her bidding for 10 minutes, unless this bidding contradicts direct orders from Strahd Von Zarovich, or cause harm to him. The Dire Wolves will fight until they'll reach 1/3 of their full HP, and then will retreat.

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.

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.

Blood Disgorge. (1/day) If Volenta has successfully fed in the past 24 hours, she can use an action to vomit rotten blood in a 15-foot cone. Each creature in the area must make a DC16 Constitution Saving Throw. On a failed save, a creature takes 18 (4d8) necrotic damage, and it can't regain hit points for 1 minute. On a successful save, the creature takes half as much damage with no additional effect.