Magic Resistance. The archmage has Advantage on saving throws against spells and other magical effects.
Spellcasting. The archmage casts one of the following spells, using Intelligence as the spellcasting ability (spell save DC 18):
At will: Alter Self, Detect Magic, Knock, Mage Armor (included in AC), Mage Hand, Polymorph, Prestidigitation
1/day: Reverse Gravity
2/day: Gaseous Form
Slow (2/Day). The archmage casts Slow, using the same spellcasting ability as Spellcasting.
Protective Magic (3/Day). The archmage casts Counterspell or Shield in response to the spell's trigger, using the same spellcasting ability as Spellcasting.
Multiattack. The archmage makes four Arcane Burst attacks.
Arcane Burst. Melee or Ranged Attack Roll: +10, reach 5 ft. or range 150 ft. Hit:27 (4d10 + 5) Force damage.
Masters of Magic