Have

Swamp

Mind Rot

Davriel, Rogue Shadowmage

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, Davriel, Rogue Shadowmage deals 2 damage to them.
−1: Target player discards a card.

Disrupting Scepter

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

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Blackmail

Target player reveals three cards from their hand and you choose one of them. That player discards that card.

Specter's Wail

Dreadship Reef

{T}: Add {C}.
{1}, {T}: Put a storage counter on Dreadship Reef.
{1}, Remove X storage counters from Dreadship Reef: Add X mana in any combination of {U} and/or {B}.

Bloodhusk Ritualist

Multikicker {B} (You may pay an additional {B} any number of times as you cast this spell.)
When Bloodhusk Ritualist enters the battlefield, target opponent discards a card for each time it was kicked.

Abyssal Specter

Flying
Whenever Abyssal Specter deals damage to a player, that player discards a card.

Diabolic Edict

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Terror

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

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

Raven's Crime

Target player discards a card.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Ravenous Rats

When Ravenous Rats enters the battlefield, target opponent discards a card.

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, draw a card.

Unburden

Target player discards two cards.
Cycling {2} ({2}, Discard this card: Draw a card.)

Dimir Signet

Delirium Skeins

Wistful Thinking

Target player draws two cards, then discards four cards.

Distress

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