Vunthris Kront'tyth

Many Faced Monster. Vunthris can change his appearance at will as well as mimicking the body and voice of anyone he has ever met perfectly, and also he has advantage on deception checks to pretend to be someone else. 

Mentally Encompassing. Vunthris can read the surface thoughts of all creatures within 60ft of him without expending an action.

Alert. Whilst conscious Vunthris cannot be surprised. 

Precision Caster. When casting attack spells Vunthris ignores half and three quarters cover. 

Spectral Warriors. When Vunthris kills a humanoid creature a spectre from its corpse, this specter will follow Vunthris' commands to the best of its ability until it dies. Resurrecting the dead creature is impossible until the spectre is killed. These spectres die after 1 day.

Onslaught 1/day. At the end of his turn Vunthris can activate his onslaught, this allows him to act again as if he has another turn. 

Never Ending Terror 1/day. At the start of his turn Vunthris can begin to commune with Orcus, until the end of his next turn he cannot act or continue to concentrate on spells, however once this is finished he regains all expended spell slots and legendary resistances and is healed 5d10+50HP. 

Legendary Resistances 3/day. When Vunthris fails a saving throw he can choose to succeed instead.

War Caster. Vunthris has advantage on concentration saving throws and he can cast spells with a casting time of 1 action as an opportunity attacks instead of making a melee attack if he wishes.

Spell-casting. Vunthris is a 20th-level spell-caster. His spell-casting ability is Charisma (spell save DC 20, +10 to hit with spell attacks). Vunthris has following spells prepared:

Cantrips (at will): Booming blade, Eldritch blast, Ray of frost, Sapping sting, Toll the dead

1st level (8 slots): Absorb elements(R), Shield(R), Bane(C), Dissonant Whispers, Hellish rebuke (R), Armour of Agathys*

2nd level (6 slots): Hold Person(C), Ray of Enfeeblement(C), Scorching ray

3rd level (6 slots): Animate Dead, Blink, Bestow Curse(C unless a 5th level slot is used), counterspell(R), Hast(C)*

4th level (6 slots): Blight, Summon Greater Demon(C), Death Ward*, Fire Shield*

5th level (6 slots): Cone of Cold, Dominate Person(C)

6th level (4 slots): Create undead, Disintegrate, Freezing Sphere

7th level (4 slots): Finger of Death, Prismatic Spray, Regenerate

8th level (2 slots): Clone, Feeblemind

9th level (2 slots): True Polymorph, Meteor Swarm, Foresight*

Spells with an * next to them are spells that Vunthris would cast on himself before an upcoming battle but only if he is aware that the fight will be happening, so this means he will not have them on him if he is ambushed.

Multi Attack. Attack three times with the sword of the wailing soul.

Sword Of The Wailing Soul. Melee Weapon Attack: +10 to hit, reach 5 ft., 1 target. Hit: 33 (3d8 + 20) necrotic damage. Attacks with this weapon also critically hit on 19s as well as 20s.

Enticing Whispers 1/day. Vunthris chooses one creature within 30ft of him, that creature must make a dc 20 Wisdom saving throw or become charmed by Vunthris, they now see Vunthris as an ally and will not attack him for the next 8 hours or until dispelled.  

Spells. Some of Vunthrises Spells use actions to cast.

Vunthris can use 1 bonus action on each of his turns as well as his regular actions, the bonus actions available to him are:

Relentless Endurance (recharge 5-6). Vunthris regains 21 (2d10+10) HP.

Deathly Hex. Vunthris picks 1 creature within 120ft of him to mark as the target of his deathly hex, until either him or the target become unconscious or Vunthris uses his bonus action to change the target of his hex, Vunthris has a +6 to hit them. Additionally when the target of his hex falls unconscious he regains 30HP and can swap the target to another creature within 120ft free of action. 

Never Let Them Rest. If Vunthris has targeted someone with his Deathly Hex ability (see above) he can then use his subsequent bonus actions to either teleport up to 30ft to them or cause the target to make a DC 20 Wisdom saving throw or take 3d10 psychic damage. 

Armour Of Hexes. When the target of Deathly Hex hits Vunthris with an attack he can force them to miss the attack.

Spells. Some of Vunthrises Spells use reactions to cast.

At the end of another creatures turn Vunthris may use one of his legendary actions from the list below, he may only use each one once per round. Vunthris has 3 legendary actions which restore at the end of his turn.

Cast Spell. Vunthris can cast a spell of 5th level or lower. 

Attack. Vunthris can make an attack with the sword of the wailing soul twice. 

Teleport. Vunthris can teleport 30ft to an unoccupied location. 

Invisibility(Costs 2). Vunthris becomes invisible until his next turn ends.