Torment of Scarabs

Enchantment — Aura Curse

Enchant player
At the beginning of enchanted player's upkeep, that player loses 3 life unless they sacrifice a nonland permanent or discard a card.

2017-07-14:
While resolving the triggered ability of Torment of Scarabs, the enchanted player 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. That player can always choose to lose 3 life, even if they have cards to discard or nonland permanents to sacrifice.