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

Regeneration. The vampire 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.

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 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.

Ghastly Retinue: Volenta fights with two ghost by her side. When fighting, the ghosts assume the form of Volenta. They are still incorporeal to the effects of physical attacks and interaction with the material plane.

Shades of the Forbidden: When fighting, Volenta and her ghosts assume different roles. At the end of round, if Volenta has been discovered, she will vanish into mist, relocate, and re-shuffle the roles of the ghosts. When one of the ghosts is defeated, the other forms gain extra properties. The defeated form doesn't appear again. Destroying a ghost deals 20 damage to Volenta.

Three forms

Form of Fury: Giant broadsword, taller than her and almost as wide. Will try to rush down a single character to death.

• Passive: Combo Attack: Attacks have advantage vs the last attacked target.
• Normal Form:
  • Cut Down: Attack twice. Cleave up 2 enemies within 5ft of each other and Volenta. +5 to hit, 3d8+15 (18/29/39) slashing damage on hit.
  • Rush Down: Shove herself at the enemy, wielding the sword as if it were a lance. Dash up to 10ft (even through occupied spaces), and attack once. +5 to hit, 3d8+15 (18/29/39) damage on hit.
• One ghost Down:
  She can dash and attack twice on the same action.

Form of Thunder: A candle and a big mace. Presses people into the form of Fury and away from the Form of Flame.

• Passive: Tactically-minded: Can dash as a bonus action.
• Normal form:
  • Short-range ghostly flame: Telegraphed. AoE in a 10ft-deep, 30ft wide arc in front of it. Wisdom Save DC15. On failure, deals 2d8 + 4 (7/18/28) psychic dmg and target is stunned. On success, just take half damage.
  • Thunder Mace: Attack twice. +5 to attack, 1d8 + 6 dmg . On hit, make a Con Save DC 15. If fails, gets knocked away 10ft.
• One Ghost down:
  • Lantern Burns Brighter: Explode at end of round: Deal 20ft AoE damage, 6d8, Dex Save DC15 for half.

Form of Flame: Wielding a lantern, will try to cast spells to control the battlefield.

• Normal form:
  • Fire missiles: Telegraphed. Three missiles, 30ft range, 10ft wide, in a cone. 3d8 + 4 (7/18/28) dmg. Dex Save DC15 for half.
  • Step and bolt: Explode in a 5ft radius explosion 3d8 + 4 (7/18/28) dmg. Dex Save DC15 for half., Disengage, run, cast magic missile.
• One Ghost down:
  • Lantern Burns Brighter: Explode at end of round: Deal 20ft AoE damage, 6d8, Dex Save DC15 for half.

Re-shuffle: If she's discovered, Volenta reshuffles at the end of the round with whatever ghosts are left. She cannot assume a destroyed form. She will re-appear in the same position, but it should be clear to the players that she's not who she says she is.