Spellcasting. The sage casts one of the following spells, using Intelligence as the spellcasting ability (save DC 16, +8 to hit with spell attacks):

At will: light, mage hand, mending, prestidigitation

1/day each: banishment, contact other plane, Drawmij's instant summons, legend lore, locate creature, planar binding, polymorph, protection from evil and good, scrying, sending, true seeing

3/day each: comprehend languages, detect magic, dispel magic, identify, levitate, locate object, Tenser's Floating Disk, unseen servant

Shocking Grasp (Cantrip). Melee Spell Attack: +8 to hit (with advantage if the target is wearing armor made of metal), reach 5 ft., one creature. Hit:13 (3d8) lightning damage, and the target can't take reactions until the start of its next turn.

Lightning Eruption (3/Day). The sage creates an eruption of magical lightning centered on a point it can see within 150 feet of it. Each creature in a 20-foot-radius sphere centered on that point must make a DC 16 Dexterity saving throw, taking 28 (8d6) lightning damage on a failed save, or half as much damage on a successful one.

Shield (1st-Level Spell; 3/Day). When the sage is hit by an attack or targeted by a magic missile spell, it calls forth an invisible barrier of magical force that protects it. Until the start of its next turn, the sage has a +5 bonus to AC, including against the triggering attack, and it takes no damage from magic missile.