While resolving Torment of Hailfire, your opponent chooses a card to be discarded without revealing it, chooses a nonland permanent to be sacrificed, or chooses to do neither. Then that player discards that card, sacrifices that permanent, or loses 3 life, then repeats this process if it hasn’t been done X times yet. Your opponent can always choose to lose 3 life, even if they have cards to discard or nonland permanents to sacrifice.