Chidori

A stroke of lightning forming around your hand or a weapon you are holding. Whenever you strike a creature it takes 6d6 of lightning damage.
The lightning ignites flammable objects in that are being worn or carried. As well as object in your environment.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3th.