As a reaction to being attacked you rebuke the attacker with heavenly white flames that cannot be extinguished unless the user uses a free action to stop them. The target affected by this spell takes 2d8 fire damage unless the target is undead in which it takes double damage from the flames(6d8). Once the target is affected the following turns until user of this spells decides to end this spell with a free action the target takes 1d8 fire damage at the start of each of the it's turns which is also doubled if target is undead.

Casting this spell at a higher level then  results in the damage of the flames increasing by 1d8 per spell level above 3rd. This also includes damage taken from flames after initial activation.