Electric execution

You extend your arm and release a deadly electric charge. Choose a creature within a 5-foot radius, it must make a Dexterity saving throw. A target takes 10d8 + 40 lightning damage on a failed save and stunned fore the end of your next turn, or half as much damage and isn't stunned on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the damage increases by 2d8 and constant damage increases by 10 for each slot level above 7th.

[Tome of spells: Lightning]