Coercion

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

Necropotence

Skip your draw step.
Whenever you discard a card, exile that card from your graveyard.
Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Duress

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

Mind Burst

Target player discards X cards, where X is one plus the number of cards named Mind Burst in all graveyards.

Mindslicer

When Mindslicer dies, each player discards their hand.

Swamp

Dark Ritual

Encroach

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

Silent Specter

Flying
Whenever Silent Specter deals combat damage to a player, that player discards two cards.
Morph {3}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control of their choice, then sacrifices a third of the lands they control of their choice. Round up each time.

Hypnotic Cloud

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Target player discards a card. If this spell was kicked, that player discards three cards instead.

Funeral Charm

Choose one —
• Target player discards a card.
• Target creature gets +2/-1 until end of turn.
• Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Ostracize

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

Probe

Kicker {1}{B} (You may pay an additional {1}{B} as you cast this spell.)
Draw three cards, then discard two cards. If this spell was kicked, target player discards two cards.

Megrim

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