Cunning Lethemancer

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

Swamp

Delirium Skeins

Professor Onyx

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.
+1: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
−3: Each opponent sacrifices a creature with the greatest power among creatures that player controls.
−8: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.

Painful Quandary

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

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

The Raven Man

At the beginning of each end step, if a player discarded a card this turn, create a 1/1 black Bird creature token with flying and "This creature can't block."
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Words of Waste

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

Dark Ritual

Vicious Rumors

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

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Raiders' Wake

Whenever an opponent discards a card, that player loses 2 life.
Raid — At the beginning of your end step, if you attacked this turn, target opponent discards a card.

Dark Deal

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

Awaken the Erstwhile

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

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.

Liliana, Waker of the Dead

+1: Each player discards a card. Each opponent who can't loses 3 life.
−3: Target creature gets -X/-X until end of turn, where X is the number of cards in your graveyard.
−7: You get an emblem with "At the beginning of combat on your turn, put target creature card from a graveyard onto the battlefield under your control. It gains haste."

Geth's Grimoire

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

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Orcish Bowmasters

Flash
When Orcish Bowmasters enters and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

Arterial Flow

Each opponent discards two cards. If you control a Vampire, each opponent loses 2 life and you gain 2 life.

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Liliana's Caress

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

Burglar Rat

When Burglar Rat enters, each 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.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Withering Boon

As an additional cost to cast this spell, pay 3 life.
Counter target creature spell.

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.")

Bottomless Pit

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

Rankle's Prank

Choose one or more —
• Each player discards two cards.
• Each player loses 4 life.
• Each player sacrifices two creatures.

Nezumi Informant

When Nezumi Informant enters, each opponent discards a card.

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Infernal Grasp

Destroy target creature. You lose 2 life.

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Sol Ring

Duress

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

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Necrogen Mists

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

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Inquisition of Kozilek

Target player reveals their hand. You choose a nonland card from it with mana value 3 or less. That player discards that card.

Planar Void

Whenever another card is put into a graveyard from anywhere, exile that card.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Tinybones, Trinket Thief

At the beginning of each end step, if an opponent discarded a card this turn, you draw a card and you lose 1 life.
{4}{B}{B}: Each opponent with no cards in hand loses 10 life.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

Tergrid, God of Fright // Tergrid's Lantern

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

Tourach, Dread Cantor

Kicker {B}{B} (You may pay an additional {B}{B} as you cast this spell.)
Protection from white
Whenever an opponent discards a card, put a +1/+1 counter on Tourach, Dread Cantor.
When Tourach enters, if it was kicked, target opponent discards two cards at random.

Megrim

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

Hypnotic Specter

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

Reliquary Tower

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Shrieking Affliction

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

Jet Medallion

Black spells you cast cost {1} less to cast.

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

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.

Oppression

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

Stabwhisker the Odious

At the beginning of each opponent's upkeep, that player loses 1 life for each card fewer than three in their hand.

Nezumi Shortfang

{1}{B}, {T}: Target opponent discards a card. Then if that player has no cards in hand, flip Nezumi Shortfang.

Nezumi Shortfang // Stabwhisker the Odious

Necrogoyf

Necrogoyf's power is equal to the number of creature cards in all graveyards.
At the beginning of each player's upkeep, that player discards a card.
Madness {1}{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.)

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

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.

Containment Construct

Whenever you discard a card, you may exile that card from your graveyard. If you do, you may play that card this turn.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Cabal Stronghold

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

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

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.

Elderfang Disciple

When Elderfang Disciple enters, each opponent discards 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.

Liliana of the Veil

+1: Each player discards a card.
−2: Target player sacrifices a creature.
−6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.