Cry of Contrition

Target player discards a card.
Haunt (When this spell card is put into a graveyard after resolving, exile it haunting target creature.)
When the creature Cry of Contrition haunts dies, target player discards a card.

Distress

Target player reveals their hand. You choose a nonland card from it. That player discards that card.

The Rack

As The Rack enters, choose an opponent.
At the beginning of the chosen player's upkeep, The Rack deals X damage to that player, where X is 3 minus the number of cards in their hand.

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature of their choice, then sacrifices a land of their choice.

Augur of Skulls

{1}{B}: Regenerate Augur of Skulls.
Sacrifice Augur of Skulls: Target player discards two cards. Activate only during your upkeep.

Shrieking Affliction

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 3 life.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.