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.

Nightmare Incursion

Search target player's library for up to X cards, where X is the number of Swamps you control, and exile them. Then that player shuffles.

Bad River

This land enters tapped.
{T}, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• This creature deals 2 damage to any target and you gain 2 life.

Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

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.

Arcane Signet

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

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: This creature gets +1/+1 until end of turn.

Ill-Gotten Gains

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

Geth's Grimoire

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

Bloodvial Purveyor

Flying, trample
Whenever an opponent casts a spell, that player creates a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Whenever this creature attacks, it gets +1/+0 until end of turn for each Blood token defending player controls.

Necrogen Mists

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

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Warped Devotion

Whenever a permanent is returned to a player's hand, that player discards a card.

Entropic Battlecruiser

Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 8+.)
1+ | Whenever an opponent discards a card, they lose 3 life.
8+ | Flying, deathtouch
Whenever this Spacecraft attacks, each opponent discards a card. Each opponent who can't loses 3 life.

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.
When Tourach enters, if it was kicked, target opponent discards two cards at random.

Empty the Catacombs

Each player returns all creature cards from their graveyard to their hand.

Monument to Endurance

Whenever you discard a card, choose one that hasn't been chosen this turn —
• Draw a card.
• Create a Treasure token.
• Each opponent loses 3 life.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Putrefaction

Whenever a player casts a green or white spell, that player discards a card.

Maestros Theater

When this land enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Swamp

Damnation

Destroy all creatures. They can't be regenerated.

Obscura Storefront

When this land enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Urborg, Tomb of Yawgmoth

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

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Veilborn Ghoul

This creature can't block.
Whenever a Swamp you control enters, you may return this card from your graveyard to your hand.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Awaken the Erstwhile

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

Tinybones, Bauble Burglar

Whenever an opponent discards a card, exile it from their graveyard with a stash counter on it.
During your turn, you may play cards you don't own with stash counters on them from exile, and mana of any type can be spent to cast those spells.
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Sol Ring

Megrim

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

Torment of Hailfire

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

Final Act

Choose one or more —
• Destroy all creatures.
• Destroy all planeswalkers.
• Destroy all battles.
• Exile all graveyards.
• Each opponent loses all counters.

Anvil of Bogardan

Players have no maximum hand size.
At the beginning of each player's draw step, that player draws an additional card, then discards a card.

Mind Sludge

Target player discards a card for each Swamp you control.

Deadly Tempest

Destroy all creatures. Each player loses life equal to the number of creatures they controlled that were destroyed this way.

Syphon Mind

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

Abyssal Nocturnus

Whenever an opponent discards a card, this creature gets +2/+2 and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Defile

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

Geier Reach Sanitarium

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

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Fell Specter

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

Bloodstained Mire

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Cabal Coffers

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

Dark Deal

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

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

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.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Espers to Magicite

Exile each opponent's graveyard. When you do, choose up to one target creature card exiled this way. Create a token that's a copy of that card, except it's an artifact and it loses all other card types.

Oppression

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

Chains of Mephistopheles

If a player would draw a card except the first one they draw in each of their draw steps, that player discards a card instead. If the player discards a card this way, they draw a card. If the player doesn't discard a card this way, they mill a card.

Painful Quandary

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

Extraplanar Lens

Imprint — When this artifact enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

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.)

Temple of the Dead

(Transforms from Aclazotz, Deepest Betrayal.)
{T}: Add {B}.
{2}{B}, {T}: Transform this land. Activate only if a player has one or fewer cards in hand and only as a sorcery.

Aclazotz, Deepest Betrayal

Flying, lifelink
Whenever Aclazotz attacks, each opponent discards a card. For each opponent who can't, you draw a card.
Whenever an opponent discards a land card, create a 1/1 black Bat creature token with flying.
When Aclazotz dies, return it to the battlefield tapped and transformed under its owner's control.

Aclazotz, Deepest Betrayal // Temple of the Dead

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if this enchantment has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Massacre

If an opponent controls a Plains and you control a Swamp, you may cast this spell without paying its mana cost.
All creatures get -2/-2 until end of turn.

Brink of Madness

At the beginning of your upkeep, if you have no cards in hand, sacrifice this enchantment and target opponent discards their hand.

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature of their choice.

Rottenmouth Viper

As an additional cost to cast this spell, you may sacrifice any number of nonland permanents. This spell costs {1} less to cast for each permanent sacrificed this way.
Whenever this creature enters or attacks, put a blight counter on it. Then for each blight counter on it, each opponent loses 4 life unless that player sacrifices a nonland permanent of their choice or discards a card.

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 token can't block."
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Bottomless Pit

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

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Liliana's Caress

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

Headless Specter

Flying
Hellbent — Whenever this creature deals combat damage to a player, if you have no cards in hand, that player discards a card at random.

Riveteers Overlook

When this land enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Skullslither Worm

When this creature enters, each opponent discards a card. For each opponent who can't, put two +1/+1 counters on this creature.

Davriel, Rogue Shadowmage

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

Hostile Investigator

When this creature enters, target opponent discards a card.
Whenever one or more players discard one or more cards, investigate. This ability triggers only once each turn. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

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.

Rocky Tar Pit

This land enters tapped.
{T}, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Quest for the Nihil Stone

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