Coercion

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

Swamp

Swamp // Swamp

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Wand of Ith

{3}, {T}: Target player reveals a card at random from their hand. If it's a land card, that player discards it unless they pay 1 life. If it isn't a land card, the player discards it unless they pay life equal to its mana value. Activate only during your turn.

Specter's Wail

Mind Twist

Target player discards X cards at random.

Memory Jar

{T}, Sacrifice Memory Jar: Each player exiles all cards from their hand face down and draws seven cards. At the beginning of the next end step, each player discards their hand and returns to their hand each card they exiled this way.

No Mercy

Whenever a creature deals damage to you, destroy it.

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Dark Ritual

Hymn to Tourach

Target player discards two cards at random.

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.

Disrupting Scepter

{3}, {T}: Target player discards a card. Activate only during your turn.

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Phyrexian Defiler

{T}, Sacrifice Phyrexian Defiler: Target creature gets -3/-3 until end of turn.

Order of Yawgmoth

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Order of Yawgmoth deals damage to a player, that player discards a card.