Vailryn the Scourged

Dark Sight. Magical darkness doesn't impede the devil's darkvision.

Mind Warped. Vailryn's mind has changed to the point of no return. She cannot be charmed, and all wisdom or charisma saving throws have advantage. 

Regeneration. At the start of every turn, Vailryn recovers 10 hit points if she has at least one remaining.

Shrill of the Afterlife. Instead of using one of her actions to cast a spell, she can instead roll her eyes back into her head. Her veins turn black and from her hand fires out black laced lines of air. They move and pivot perfectly into opponents mouths. They must make a DC 16 constitution saving throw, If they fail, they take 16 (4d8 + 4) necrotic damage and become blinded and frightened for 1 turn. If they succeed they take half damage and are not blinded or frightened.

Grave Plain. As a bonus action at the end of her turn, Vailryn can can summon a black portal underneath her feet and disappear into it. She has disappeared until the start of her turn where she has reappeared at maximum 60 feet away.

Bound Shield. When something is reduced down to 0hp within her line of sight, including herself. She can use her reaction to cast a black shield around them from falling unconscious and living with 1hp.

Spell Casting. Vailryn is a 16th level spell caster with her Intelligence as her spell casting ability. She has DC 17 and +10 to hit. She has several spells she can cast ranging from a 16th level wizard with those spells being. 

False life, Vampiric Touch, Shadow of Moil, Finger of Death, Danse Macabre, Enervation, Animate dead, Bestow Curse, Spirit Shroud, Blight and Summon Undead.

Multispell. Vailryn has the ability to cast two spells a turn.

Life Steal. When Vailryn is within 5 feet of someone, she makes an attack role of +10. If succefully hit, she reaches her hand out and grips their face. Her victim and herself veins both become black and eyes roll into the back of their head. They must make a constitution saving throw of DC 17. Failing means they take 8d6 necrotic damage and are afflicted with poison. Succeeding means they take half damage and aren't poisoned. How much damage she deals, she recovers half of that hp.

Grave Plain. As a bonus action Vailryn disappears into the ground, no longer on the battle field and can not be attacked. At the start of her next turn, she can reappear where ever at a maximum range of 60 feet.

Bound Shield. Is casted when she someone is reduced to 0hp in her line of sight. A black ward of shields surround them and they survive with 1hp. 

Vailryn has three legendary actions and regains one every turn.

Necrosis Volley (Cost 1) Can cast another spell on their action.

Underworld Re-life (Cost 3) Vailryn can increase vitality in the undead, including herself, every undead within 30 feet of her regains 25 hit points.