Ameterasu

As an Action the wielder creates a black magical fire in a 10 X 10 feet square in an area he/she can see. Any creature in that region must make a Dexterity save of DC 13 ( or Caster's spell casting DC, whichever is higher) on a fail it takes 2dl0 fire damage and an ongoing 5 fire damage at start of each turn, this can't be removed without a spell. On a successful save the target takes no damage and shifts out of that area.