Knife of Stolen Resistance

Using an action, you carve a single infernal rune into the flesh of an Unconscious Beast, Celestial, Dragon, Fey, or Giant with this knife. Over the next 10 minutes the creature dies an agonizing death that can't be prevented short of the Wish spell. If the creature has any resistances or immunities, you gain those resistances and immunities until the creature dies or a Wish spell is used to save the creature. The knife's power can't be used again until you finish a long rest.