From Hell’s Heart
When you summon fire with any of your moves, you can replace it with the black fires of hell itself.
This fire does not burn with heat and ignores armor, scorching the soul itself.
Those creatures without souls cannot be harmed by this type of flame.
The information on this site is based on the works of Sage LaTorra and Adam Koebel.
More information can be found at the Dungeon World Official Website.