Ball lightning

A bright blue streak flashes from your pointing finger to a point you choose within range and then blossoms with a thunderous crackling roar into an giant blue flash. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 12d4 lightning damage on a failed save, or half as much damage on a successful one.

The lightning spreads around corners. Any constructs in the area must make a constitution save and on a failed save be stunned for until the end of their next turn.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 2d4 for each slot level above 3rd, additionally When cast at a higher level, the constitution save against stun is raised by 1 per level the spell is upcast