Claws of Lightning

You call the power within to electrify your unarmed attacks, engulfing your hands and arms full of electricity, but you continue to take damage from the immense energy, for 1 minute you gain the following; Your unarmed attacks deal 2d8 lighting damage per hit, but take 1d4 per turn. 

At Higher Levels. When you cast this spell using a spell slot 3rd level or higher, the damage increases by 1d8 and 1d4 for each slot level above 3rd.