Alaesar the Bright

Magic Resistance. Alaesar has advantage on saving throws against spells and other magical effects.

False Aura. Alaesar gives off no magical aura and none of his magic is revealed by the detect magic spell.

Legendary Resistance (3/Day). If Alaesar fails a saving throw, he can choose to succeed 

Master Illusionist. Alaesar can maintain concentration on any two illusion spells simultaneously. Alaesar can make any illusion create sounds, smells, and sight.

Crown of the Master Illusionist. Alaesar's crown gives him true-sight for 90 feet and allows him advantage on saving throws against all illusion magic. 

Robe of Scintillating Colors. This robe has 3 charges, and it regains 1d3 expended charges daily at dawn. While you wear it, you can use an action and expend 1 charge to cause the garment to display a shifting pattern of dazzling hues until the end of your next turn. During this time, the robe sheds bright light in a 30-foot radius and dim light for an additional 30 feet. Creatures that can see you have disadvantage on attack rolls against you. In addition, any creature in the bright light that can see you when the robe's power is activated must succeed on a DC 15 Wisdom saving throw or become stunned until the effect ends.

Spellcasting. The archmage is an 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 21, +13 to hit with spell attacks). The archmage can cast disguise self, major image, and invisibility at will and has the following wizard spells prepared:

Cantrips (at will): minor illusion, light, mage hand, prestidigitation, chill touch

1st level (5 slots): detect magic, identify, mage armor*, magic missile, absorb elements

2nd level (5 slots): detect thoughts, mirror image*, misty step, color spray, phantasmal force

3rd level (4 slots): counterspell, fly, lightning bolt, phantasmal killer

4th level (4 slots): banishment, greater invisibility, hallucinatory terrain, vitriolic sphere

5th level (4 slots): seeming, scrying, wall of force, mislead, hold monster

6th level (3 slot): disintegrate, mental prison, programmed illusion, scatter

7th level (2 slot): mirage arcane, teleport, simulacrum, prismatic spray, project image

8th level (2 slot): illusory dragon

9th level (1 slot): weird, psychic scream

*The archmage casts these spells on itself before combat. 

Dagger. Melee or Ranged Weapon Attack: +9 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 5 (1d4 + 3) piercing damage.

Illusory Self. Alaesar can create an illusory duplicate of himself as an instant, almost instinctual reaction to danger. When a creature makes an attack roll against him, he can use his reaction to interpose the illusory duplicate between the attacker and himself. The attack automatically misses him, then the illusion dissipates.

He can use this feature twice a day. He will do this twice before using his mirror image selves.

Absorb Elements. Alaesar casts the Absorb elements spell from his known spells.

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

Cantrip. (1 action) Alaesar casts a cantrip he knows that normally takes an action.

Manipulate illusion (1 action) Alaesar can change or move any major, programmed, or minor illusion he is currently sustaining.

Realize illusion. (1 action) Alaesar can turn any one illusion he has created into a real object or reverse this same effect. Alaesar must still concentrate on the manifested illusions or they will disappear.

Misty Step. (2 action) Alaesar can misty step to any space he can see within 30 feet. He must use a second level spell slot to use this.

Flash. (2 Actions) Alaesar flashes with bright white light. Any creatures within 5 feet of him must make a DC 21 Constitution saving throw or become blinded for 1 round.

Cast a Spell. (3 Actions) Alaesar can cast any spell of 4th level or lower.