Dark Flame

A black flame engulfs one target (creature or structure) dealing 10D8 Fire,10D8 Necrotic &  10D8 Radiant damage per turn until the target and anything the target contains or is wearing are consumed completely.  nothing less than a wish spell can dispel this flame, but if a wish spell is not cast to dispel it the damage can not be reversed except by an overgod. This spell can destroy even artifacts it is also the only known way to destroy the tarrasque without a wish spell. Upon worlds where the gods of magic have not limited spells to 9th level or below this can be upcast to up to 12th level doubling the damage for each level higher that is used to cast this spell above 9th.