Demonfire is a rare Sorcery card from Dissension (DIS), collector number 60. Current market price: $0.54 (foil $5.99), TCGplayer market prices via Scryfall.
Demonfire deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead. Hellbent — If you have no cards in hand, this spell can't be countered and the damage can't be prevented.