Master Sage

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

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.

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.