Boltwave

A burst of arcing lighting erupts from you in a 40-foot emanation. Each creature in the Emanation makes a Dexterity saving throw, taking 2d6 Lightning damage on a failed save or half as much damage on a successful one. If a creature fails the save by 5 or more, they are paralyzed until the start of your next turn.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 2.