Bagrol Vrakus

Alteration of Flame.  When Bagrol makes an attack or casts a spell that deals Fire, Lightning, or Necrotic damage, he can change the damage type to any of the other two.

Fade Out. When Bagrol is in an area of dim light or darkness, he can use an action to become invisible until he moves or takes an action or reaction.

Guarded Mind. Bagrol's thoughts cannot be read by telepathy or any other means unless he allows it.

Undying Resilience (1/Day).  When Bagrol first falls to 0 hit points, he instead falls to 1.  This ability recharges each dawn.

Spellcasting. Bagrol is a 20th-level spellcaster.  His spellcasting ability is Charisma (spell save DC 23, +15 to hit with spell attacks).  Bagrol has the following spells prepared:

Cantrips (at will): Prestidigitation, Mending, Minor Illusion, Eldritch Blast

1st level (4 slots): Charm Person, Detect Magic

2nd level (3 slots): Darkness, Detect Thoughts

3rd level (3 slots): Counterspell, Dispel Magic, Haste, Lightning Bolt

4th level (3 slots): Greater Invisibility

5th level (3 slots): Hold Monster

6th level (2 slots): Eyebite, Tasha's Otherworldly Guise

7th level (2 slots): Power Word Pain, Teleport

8th level (1 slot): Dominate Monster

9th level (1 slot): Gate, True Polymorph

Multiattack.  Bagrol uses one Blade of the Eclipse attack or one Invoke Flame attack and uses Spellcasting.

Blade of the Eclipse. Melee Weapon Attack: +9 to hit, reach 5 ft., 1 target. Hit: 5 (1d6 + 3) piercing damage, plus 18 (3d12) necrotic damage. 

Invoke Flame. Melee or Ranged Spell Attack: +15 to hit, reach 5 feet or range 120 feet, one target. Hit: 22 (5d6 + 5) of a type of Bagrol's choice: necrotic, fire, or lightning.

Shadow Walk. When Bagrol is in dim light or darkness, as a bonus action, he can magically teleport up to 120 ft. to an unoccupied space he can see that is also in dim light or darkness.

Pluck the Strings. (3/Day) Bagrol utilizes the Purple Flame to pluck the strings of fate.  When Bagrol or a creature he can see within 120 feet of him makes an attack roll, ability check, or a saving throw, he can use his reaction to ignore the die roll and decide whether the outcome is that of a success or failure.

Bagrol can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature’s turn. Bagrol regains spent legendary actions at the start of his turn.

Attack. Bagrol makes one Blade of the Eclipse attack.

Rapid Spellcasting.  Bagrol casts one spell that does not deal damage and costs a spell slot of 5th or lower.

Fatebreaker (Costs 2 Actions).  Bagrol targets a creature within 60 feet of him.  Until the end of Bagrol's next turn, or until he uses another legendary action, the targeted creature gains disadvantage on all attacks, ability checks, and saving throws.