Continuous Lightning

You create a bolt of lightning that targets one creature of your choice in a 20 radius centered on you. The target must make a dexterity saving throw. It takes 4d8 lightning damage on a failed save or half as much on a successful one. On a failed save, the lightning keeps hitting the target continuously, and it takes 3d8 lightning damage on each of the creatures turns. The creature can repeat the saving throw in the end of its turn, after taking the damage.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 in the first strike, and you can target one more creature, for each slot level above 3rd.