Nester

Nester has advantage on saving throws against spells and other magical effects.

Nester 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:

At will: disguise self, invisibility

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

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

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

Level 3 (3 slots): counterspell, animate dead, lightning bolt

Level 4 (3 slots): blight, fire shield, stoneskin*

Level 5 (3 slots): cone of cold, Rary's telepathic bond, wall of force

Level 6 (1 slots): globe of invulnerability

Level 7 (1 slots): teleport

Level 8 (1 slots): mind blank*

Level 9 (1 slots): time stop

*Nester casts these spells on itself before combat.

Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 4 (1d4 + 2) piercing damage.