You flourish a weapon you are proficient with used in the casting and then whirl around, igniting it in a whirling conflagration. Make a melee weapon attack against each target with 15ft. Each target takes 6d6 fire damage on a hit, or half as much if you miss. 

At higher levels: When you cast this spell using a spell slot of 4th Level or higher, it deals an additional 1d6 to each target for each spell level above 3rd.