Electric nail

You touch one willing creature and a fervent of lightning covers your hands. Until the spell ends, the caster can use its action to electrify a creature within 15 feet of it as an action. The target of the electricity must make a Constitution saving throw, taking 3d8 lightning damage on a failed save, or half as much on a successful one. The target has a disadvantage if it is wearing metal armor. 

    At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the caster of the spell can target a creature that is an additional 5 feet away from it for each slot level above 2nd