Have

Sol Ring

Hollow Specter

Flying
Whenever Hollow Specter deals combat damage to a player, you may pay {X}. If you do, that player reveals X cards from their hand and you choose one of them. That player discards that card.

Guul Draz Specter

Flying
Guul Draz Specter gets +3/+3 as long as an opponent has no cards in hand.
Whenever Guul Draz Specter deals combat damage to a player, that player discards a card.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

Creeping Dread

At the beginning of your upkeep, each player discards a card. Each opponent who discarded a card that shares a card type with the card you discarded loses 3 life. (Players reveal the discarded cards simultaneously.)

Bone Miser

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

Quest for the Nihil Stone

Whenever an opponent discards a card, you may put a quest counter on Quest for the Nihil Stone.
At the beginning of each opponent's upkeep, if that player has no cards in hand and Quest for the Nihil Stone has two or more quest counters on it, you may have that player lose 5 life.

Smallpox

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

Swamp

Cabal Pit

{T}: Add {B}. Cabal Pit deals 1 damage to you.
Threshold — {B}, {T}, Sacrifice Cabal Pit: Target creature gets -2/-2 until end of turn. Activate only if seven or more cards are in your graveyard.

Scythe Specter

Flying
Whenever Scythe Specter deals combat damage to a player, each opponent discards a card. Each player who discarded a card with the highest mana value among cards discarded this way loses life equal to that mana value.

Liliana's Reaver

Deathtouch
Whenever Liliana's Reaver deals combat damage to a player, that player discards a card and you create a tapped 2/2 black Zombie creature token.

Herald of Anguish

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Flying
At the beginning of your end step, each opponent discards a card.
{1}{B}, Sacrifice an artifact: Target creature gets -2/-2 until end of turn.

Guiltfeeder

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Guiltfeeder attacks and isn't blocked, defending player loses 1 life for each card in their graveyard.

Greel, Mind Raker

{X}{B}, {T}, Discard two cards: Target player discards X cards at random.

Nighteyes the Desecrator

{4}{B}: Put target creature card from a graveyard onto the battlefield under your control.

Nezumi Graverobber

{1}{B}: Exile target card from an opponent's graveyard. If no cards are in that graveyard, flip Nezumi Graverobber.

Nezumi Graverobber // Nighteyes the Desecrator

Cunning Lethemancer

At the beginning of your upkeep, each player discards a 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.

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

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, then sacrifices a third of the lands they control. Round up each time.

Archfiend of Ifnir

Flying
Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.
Cycling {2} ({2}, Discard this card: Draw a card.)

Death Cloud

Each player loses X life, discards X cards, sacrifices X creatures, then sacrifices X lands.

Enemy of Enlightenment

Flying
Enemy of Enlightenment gets -1/-1 for each card in your opponents' hands.
At the beginning of your upkeep, each player discards a card.

Geth's Grimoire

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

Mindslicer

When Mindslicer dies, each player discards their hand.

Rackling

At the beginning of each opponent's upkeep, Rackling deals X damage to that player, where X is 3 minus the number of cards in their hand.

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.

Mind Sludge

Target player discards a card for each Swamp you control.

Fell Specter

Flying
When Fell Specter enters, target opponent discards a card.
Whenever an opponent discards a card, that player loses 2 life.

Bottomless Pit

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

Locust Miser

Each opponent's maximum hand size is reduced by two.

Delirium Skeins

Thran Dynamo

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Mind Shatter

Target player discards X cards at random.

Banshee of the Dread Choir

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Banshee of the Dread Choir deals combat damage to a player, that player discards a card.

Rankle, Master of Pranks

Flying, haste
Whenever Rankle, Master of Pranks deals combat damage to a player, choose any number —
• Each player discards a card.
• Each player loses 1 life and draws a card.
• Each player sacrifices a creature.

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Words of Waste

{1}: The next time you would draw a card this turn, each opponent discards a card instead.

Beacon of Unrest

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

Ill-Gotten Gains

Exile Ill-Gotten Gains. Each player discards their hand, then returns up to three cards from their graveyard to their hand.

Noetic Scales

At the beginning of each player's upkeep, return to its owner's hand each creature that player controls with power greater than the number of cards in their hand.

Hypnotic Specter

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

Mind Twist

Liliana's Caress

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

Awaken the Erstwhile

Each player discards all the cards in their hand, then creates that many 2/2 black Zombie creature tokens.

Megrim

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

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Oppression

Whenever a player casts a spell, that player discards a card.

Cabal Conditioning

Any number of target players each discard a number of cards equal to the highest mana value among permanents you control.

Shrieking Affliction

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

Larceny

Whenever a creature you control deals combat damage to a player, that player discards a card.

Gibbering Descent

At the beginning of each player's upkeep, that player loses 1 life and discards a card.
Hellbent — Skip your upkeep step if you have no cards in hand.
Madness {2}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Urgoros, the Empty One

Flying
Whenever Urgoros, the Empty One deals combat damage to a player, that player discards a card at random. If the player can't, you draw a card.

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Leechridden Swamp

({T}: Add {B}.)
Leechridden Swamp enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Cao Cao, Lord of Wei

{T}: Target opponent discards two cards. Activate only during your turn, before attackers are declared.

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.)

Stronghold Rats

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Stronghold Rats deals combat damage to a player, each player discards a card.

Bloodhusk Ritualist

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

Liliana's Specter

Flying
When Liliana's Specter enters, each opponent discards a card.

Capital Punishment

Council's dilemma — Starting with you, each player votes for death or taxes. Each opponent sacrifices a creature for each death vote and discards a card for each taxes vote.

Wheel of Torture

At the beginning of each opponent's upkeep, Wheel of Torture deals X damage to that player, where X is 3 minus the number of cards in their hand.

Tasigur's Cruelty

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Each opponent discards two cards.

The Haunt of Hightower

Flying, lifelink
Whenever The Haunt of Hightower attacks, defending player discards a card.
Whenever a card is put into an opponent's graveyard from anywhere, put a +1/+1 counter on The Haunt of Hightower.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Mind Rake

Target player discards two cards.
Overload {1}{B} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")