Chancellor Owusu

Boon of Immortality. Chancellor Owusu is immune to any effect that would age him, and he can’t die from old age.

Legendary Resistance (3/Day). If   Chancellor Owusu fails a saving throw, he can choose to succeed instead.Magic Resistance. The archmage has advantage on saving throws against spells and other magical effects.

Fey Ancestry. They have advantage on saving throws against being charmed, and magic can’t put them to sleep.

The archmage is an 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 17, +9 to hit with spell attacks). The archmage can cast disguise self and invisibility at will and has the following wizard spells prepared:

Cantrips (at will): fire bolt, light, mage hand, prestidigitation, shocking grasp

1st level (4 slots): detect magic, identify, mage armor*, magic missile

2nd level (3 slots): detect thoughts, mirror image, misty step

3rd level (3 slots): counterspell, fly, lightning bolt

4th level (3 slots): banishment, fire shield, stoneskin*

5th level (3 slots): cone of cold, scrying, wall of force

6th level (1 slot): globe of invulnerability

7th level (1 slot): teleport

8th level (1 slot): mind blank*

9th level (1 slot): time stop

*The archmage casts these spells on itself before combat.

Portent (Recharges after the Diviner Casts a Divination Spell of 1st Level or Higher). When the diviner or a creature it can see makes an attack roll, a saving throw, or an ability check, the diviner can roll a d20 and choose to use this roll in place of the attack roll, saving throw, or ability check.

Multiattack. Chancellor Owusu makes two Bewitching Bolt attacks.

Bewitching Bolt. Melee or Ranged Spell Attack: +16 to hit, reach 5 ft. or range 120 ft., one target. Hit: 25 (5d6 + 8) lightning damage, and if the target is a creature, it must succeed on a DC 22 Wisdom saving throw or be charmed by Chancellor Owusu until the start of his next turn.

Summon Demon (3/Day). The chancellor magically summons a quasit, or attempts to summon a shadow demon with a 50 percent chance of success. The summoned demon appears in an unoccupied space within 60 feet of its summoner, acts as an ally of its summoner, and can’t summon other demons. It remains for 10 minutes, until it or its summoner dies, or until its summoner dismisses it as an action.

Negate Spell (2/Day). When Chancellor Owusu sees a creature within 60 feet of his casting a spell, he tries to interrupt it. If the creature is casting a spell using a spell slot of 8th level or lower, its spell fails and has no effect. If it is casting a 9th-level spell, it must succeed on a DC 22 Intelligence saving throw, or the spells fails and has no effect.

Fey Step. Chancellor Owusu teleports, along with any equipment he is wearing or carrying, to an unoccupied space he can see within 30 feet of him.

Fey Beguilement (Costs 3 Actions). Chancellor Owusu targets one creature he can see within 60 feet of him. The target must succeed on a DC 22 Charisma saving throw or be possessed by a fey spirit. While possessed, the target must obey Chancellor Owusu commands. The target can repeat the saving throw at the end of each of its turns, banishing the fey spirit and ending the effect on itself on a success.