Arc Strike

As a bonus action, you conjure magical lightning to dance on the weapon you strike with, dealing an extra 2d8 Lightning damage to the target. In addition, the target must succeed on a Dexterity saving throw. On a failed save, the target is Stunned until the end of your next turn.

At Higher Levels. When you cast this spell using a spell slot of 3rd–Level or higher, the Lightning damage increases by 1d8 for each slot level above 2nd–Level.