In Relic, this threat card says something along the lines of 'If you win, you may discard 1 corruption card. If you do not, gain 1 corruption card".
I interpreted this as if you win the battle, you have to discard one corruption card. If you choose not to (or if you have no corruption to discard), you must gain 1 corruption card.
Another one of the players claimed that it meant if you lose the battle, you draw 1 corruption card (in addition to losing 1 life).
Which interpretation is correct?