By your command, a creature that is attacking you is momentarily engulfed in hellish flames. The creature must make a Dexterity saving throw. It takes 3d6 fire damage on a failed save, or half as much damage on a successful one. The creature takes this damage before it resolves the triggering attack roll.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 2d6 for each slot level above 1st.