Black Lightning

A Bolt of lightning suddenly comes down from the sky at the designated location, a creature in that location must make a Dexterity saving throw. A creature takes 6d8 lightning damage on a failed save, or half as much damage on a successful one.

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