Cabal Stronghold

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

James

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.

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.)

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Megrim

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

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.

Karn Liberated

+4: Target player exiles a card from their hand.
−3: Exile target permanent.
−14: Restart the game, leaving in exile all non-Aura permanent cards exiled with Karn Liberated. Then put those cards onto the battlefield under your control.

Have

Abyssal Nocturnus

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

Pilfer

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

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.

Swamp

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Oppression

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

Skirge Familiar

Crypt Incursion

Exile all creature cards from target player's graveyard. You gain 3 life for each card exiled this way.

Darkness

Prevent all combat damage that would be dealt this turn.

Bojuka Bog

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

In Another Deck

Arcane Signet

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

Ob Nixilis Reignited

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

Burglar Rat

When this creature enters, each opponent discards a card.

Beseech the Queen

({2/B} can be paid with any two mana or with {B}. This card's mana value is 6.)
Search your library for a card with mana value less than or equal to the number of lands you control, reveal it, put it into your hand, then shuffle.

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Buried Ruin: Return target artifact card from your graveyard to your hand.

Necrogen Mists

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

Foul Play

Destroy target creature with power 2 or less. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Blast Zone

Blast Zone enters with a charge counter on it.
{T}: Add {C}.
{X}{X}, {T}: Put X charge counters on Blast Zone.
{3}, {T}, Sacrifice Blast Zone: Destroy each nonland permanent with mana value equal to the number of charge counters on Blast Zone.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Thought Vessel

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

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.

Xiahou Dun, the One-Eyed

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)
Sacrifice Xiahou Dun, the One-Eyed: Return target black card from your graveyard to your hand. Activate only during your turn, before attackers are declared.

Baleful Mastery

You may pay {1}{B} rather than pay this spell's mana cost.
If the {1}{B} cost was paid, an opponent draws a card.
Exile target creature or planeswalker.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Rotting Rats

When Rotting Rats enters, each player discards a card.
Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Crucible of Worlds

Reliquary Tower

Agadeem, the Undercrypt

As Agadeem, the Undercrypt enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Agadeem's Awakening

Return from your graveyard to the battlefield any number of target creature cards that each have a different mana value X or less.

Agadeem's Awakening // Agadeem, the Undercrypt

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.)

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.

Thespian's Stage

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

Cunning Lethemancer

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

Mindlash Sliver

All Slivers have "{1}, Sacrifice this permanent: Each player discards a card."

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Plaguecrafter

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

Words of Waste

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

Geth's Grimoire

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

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.

Strip Mine

{T}: Add {C}.
{T}, Sacrifice Strip Mine: Destroy target land.

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.

Dread Presence

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

Charcoal Diamond

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

Painful Quandary

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

Erebos's Intervention

Choose one —
• Target creature gets -X/-X until end of turn. You gain X life.
• Exile up to twice X target cards from graveyards.

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.)

Liliana's Caress

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

Soulblade Corrupter

Partner with Soulblade Renewer (When this creature enters, target player may put Soulblade Renewer into their hand from their library, then shuffle.)
Deathtouch
Whenever a creature with a +1/+1 counter on it attacks one of your opponents, that creature gains deathtouch until end of turn.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Geier Reach Sanitarium

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

Mindcrank

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

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Bad Moon

Deadly Rollick

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

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.

Sorin Markov

+2: Sorin Markov deals 2 damage to any target and you gain 2 life.
−3: Target opponent's life total becomes 10.
−7: You control target player during that player's next turn.

Delirium Skeins

Volrath's Dungeon

Pay 5 life: Destroy Volrath's Dungeon. Any player may activate this ability but only during their turn.
Discard a card: Target player puts a card from their hand on top of their library. Activate only as a sorcery.

Faith of the Devoted

Whenever you cycle or discard a card, you may pay {1}. If you do, each opponent loses 2 life and you gain 2 life.

Magus of the Coffers

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

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.

Jet Medallion

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

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.

Deserted Temple

{T}: Add {C}.
{1}, {T}: Untap target land.

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.

No Mercy

Whenever a creature deals damage to you, destroy it.

Dark Favor

Enchant creature
When Dark Favor enters, you lose 1 life.
Enchanted creature gets +3/+1.

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."

Myriad Landscape

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

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

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 of their choice.