Voltraxis

A surge of electricity strikes a target within range. The target must make a Dexterity saving throw, taking 4d6 lightning damage on a failed save. If the target fails, the bolt arcs to one additional creature within 10 feet, dealing half damage to the second target.

At Higher Levels:
When cast using a spell slot of 3rd level or higher, the damage increases by 1d6 per slot level above 2nd.