Adven's Fiery Fists

You quickly wrap a willing creatures hands in wrappings and smear phosphorus across them and their hands begin to glow a fiery orange. That creature's melee attacks, using either the body or weapons, now deal an extra 4d6 fire damage on a failed save and half as much on a successful one.

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