Archmage Imperator of Torinth, Visha

Magic Resistance. Visha has Advantage on saving throws against spells and other magical effects.

Unholy Protection. When Visha is attacked, the attacker takes 5 (1d10) fire damage.

Hellish Resistance (3/Day). If Visha would fail a saving throw, she can consume a soul bag to succeed it instead.

Soul Bags. When Visha kills a creature, she can seal their soul in a bag, to a maximum of five soul bags at any given time. Visha can consume a soul bag to trigger one of the following effects (effects cannot stack on themselves):

Gain a +5 bonus to AC for 3 rounds.

Cast a level 3 or lower spell off the Wizard spell list at no action cost.

Gain 50 temporary HP.

Gain a +5 bonus to attack rolls against a specific creature.

Gain a +11 (2d10) damage bonus against a specific creature.

Consuming five soul bags at once allows Visha to cast one level 9 spell from the Wizard spell list (except Wish).

Multiattack. Visha makes four attacks.

Infernal Burst. Melee or Ranged Attack Roll: +11, reach 5 ft. or range 150 ft. Hit: 38 (6d10 + 5) Fire damage.

Arcane Cleave. Melee or Ranged Attack Roll: +11, reach 5 ft. Hit: 27 (4d10 + 5) Slashing damage. The target is pushed backwards 10ft.

Spellcasting. The archmage casts one of the following spells, using Intelligence as the spellcasting ability (spell save DC 19):

At Will: Detect Magic, Detect Thoughts, Disguise Self, Invisibility, Light, Mage Armor (included in AC), Mage Hand, Prestidigitation, Cloud of Daggers
2/Day Each: Fly, Lightning Bolt (level 7 version), Fireball (level 7 version)
1/Day Each: Cone of Cold (level 9 version), Psychic Scream, Scrying, Teleport, Meteor Swarm

Misty Step (6/Day). Visha casts Misty Step, using the same spellcasting ability as Spellcasting.

Protective Magic (6/Day). Visha casts Counterspell or Shield in response to the spell’s trigger, using the same spellcasting ability as Spellcasting.

Retribution (6/Day). Visha casts Hellish Rebuke (level 6 version) in response to an attack against her.