Archmage

Medium or Small Humanoid (Wizard), Neutral

AC 17 Initiative +7 (17)
HP 170 (31d8 + 31)
Speed 30 ft.

Skills Arcana +13, History +9, Perception +6
Immunities Psychic; Charmed (with Mind Blank)
Gear Wand
Senses Passive Perception 16
Languages Common plus five other languages
CR 12 (XP 8,000; PB +4)

Traits

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

Actions

Multiattack. The archmage makes four Arcane Burst attacks.

Arcane Burst. Melee or Ranged Attack Roll: +9, reach 5 ft. or range 150 ft. Hit: 27 (4d10 + 5) Force damage.

Spellcasting. The archmage casts one of the following spells, using Intelligence as the spellcasting ability (spell save DC 17):
 At Will: Detect Magic, Detect Thoughts, Disguise Self, Invisibility, Light, Mage Armor (included in AC), Mage Hand, Prestidigitation
 2/Day Each: Fly, Lightning Bolt (level 7 version)
 1/Day Each: Cone of Cold (level 9 version), Mind Blank (cast before combat), Scrying, Teleport

Bonus Actions

Misty Step (3/Day). The mage casts Misty Step, using the same spellcasting ability as Spellcasting.

Reactions

Protective Magic (3/Day). The archmage casts Counterspell or Shield in response to the spell’s trigger, using the same spellcasting ability as Spellcasting.