Magic Resistance. The archmage has advantage on saving throws against spells and other magical effects.
Spellcasting. 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:
6th level (1 slot): globe of invulnerability
7th level (1 slot): teleport
8th level (1 slot): mind blank
9th level (1 slot): time stop
Dagger. Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 4 (1d4 + 2) piercing damage.
Archmages are powerful (and usually quite old) spellcasters dedicated to the study of the arcane arts. Benevolent ones counsel kings and queens, while evil ones rule as tyrants and pursue lichdom. Those who are neither good nor evil sequester themselves in remote towers to practice their magic without interruption. An archmage typically has one or more apprentice mages, and an archmage's abode has numerous magical wards and guardians to discourage interlopers.