black lightning

You create a bolt of lightning that arcs toward a target of your choice that you can see within range. Three bolts then leap from that target to as many as three other targets, roll 2d6 lightning  and for every enemy divide the damage by 2 to determin the damage

At Higher Levels. When you cast this spell at 7th level or higher deal an extra 2d6 lightning damge per 4 levels