In variants that have vulnerability to elements, especially as a temporary debuff that the player can be inflicted with, you should be able to remove the debuff by doing something that would give you intrinsic resistance to that element (such as eating a corpse or tin).

Another possibility, not mutually exclusive, is that you should be able to stack multiple sources of the resistance to negate or reduce the severity of the vulnerability - i.e. two extrinsic sources of the resistance, or intrinsic resistance paired with an extrinsic.