Mogis, God of Slaughter

Indestructible
As long as your devotion to black and red is less than seven, Mogis isn't a creature.
At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature.

Night's Whisper

Hero's Downfall

Shadowblood Ridge

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.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Barren Moor

Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Dragonskull Summit

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Command Tower

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

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Last One Standing

Choose a creature at random, then destroy the rest.

Bloodfell Caves

Bloodfell Caves enters the battlefield tapped.
When Bloodfell Caves enters the battlefield, you gain 1 life.
{T}: Add {B} or {R}.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Fire Diamond

Fire Diamond enters the battlefield tapped.
{T}: Add {R}.

Sol Ring

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Mountain

Ribbons

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Each opponent loses X life.

Cut // Ribbons

Theater of Horrors

At the beginning of your upkeep, exile the top card of your library.
During your turn, if an opponent lost life this turn, you may play lands and cast spells from among cards exiled with Theater of Horrors.
{3}{R}: Theater of Horrors deals 1 damage to target opponent or planeswalker.

Forgotten Cave

Forgotten Cave enters the battlefield tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Charcoal Diamond

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

Palace Siege

As Palace Siege enters the battlefield, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, return target creature card from your graveyard to your hand.
• Dragons — At the beginning of your upkeep, each opponent loses 2 life and you gain 2 life.

Spellshock

Whenever a player casts a spell, Spellshock deals 2 damage to that player.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Rakdos Signet

Rakdos Guildgate

Rakdos Guildgate enters the battlefield tapped.
{T}: Add {B} or {R}.

Akoum Refuge

Akoum Refuge enters the battlefield tapped.
When Akoum Refuge enters the battlefield, you gain 1 life.
{T}: Add {B} or {R}.

Demonic Tutor

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

Rocky Tar Pit

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

Bedevil

Destroy target artifact, creature, or planeswalker.

Geier Reach Sanitarium

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

Mind Stone

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

Dire Fleet Ravager

Menace, deathtouch
When Dire Fleet Ravager enters the battlefield, each player loses a third of their life, rounded up.

Smoke

Players can't untap more than one creature during their untap steps.

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

Subversion

At the beginning of your upkeep, each opponent loses 1 life. You gain life equal to the life lost this way.

Fraying Omnipotence

Each player loses half their life, then discards half the cards in their hand, then sacrifices half the creatures they control. Round up each time.

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Star Compass

Star Compass enters the battlefield tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Sulfuric Vortex

At the beginning of each player's upkeep, Sulfuric Vortex deals 2 damage to that player.
If a player would gain life, that player gains no life instead.

Rakdos Carnarium

Rakdos Carnarium enters the battlefield tapped.
When Rakdos Carnarium enters the battlefield, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Oppression

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

Angrath's Marauders

If a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Tainted Peak

{T}: Add {C}.
{T}: Add {B} or {R}. Activate only if you control a Swamp.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Jokulhaups

Destroy all artifacts, creatures, and lands. They can't be regenerated.

Sire of Insanity

At the beginning of each end step, each player discards their hand.

Fate Unraveler

Whenever an opponent draws a card, Fate Unraveler deals 1 damage to that player.

Spiteful Visions

At the beginning of each player's draw step, that player draws an additional card.
Whenever a player draws a card, Spiteful Visions deals 1 damage to that player.

Zo-Zu the Punisher

Whenever a land enters the battlefield, Zo-Zu the Punisher deals 2 damage to that land's controller.

Worn Powerstone

Worn Powerstone enters the battlefield tapped.
{T}: Add {C}{C}.

Thran Dynamo

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Sign in Blood

Target player draws two cards and loses 2 life.

Swamp

Ankh of Mishra

Whenever a land enters the battlefield, Ankh of Mishra deals 2 damage to that land's controller.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Foreboding Ruins

As Foreboding Ruins enters the battlefield, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters the battlefield tapped.
{T}: Add {B} or {R}.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Syphon Mind

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

Ill-Gotten Inheritance

At the beginning of your upkeep, Ill-Gotten Inheritance deals 1 damage to each opponent and you gain 1 life.
{5}{B}, Sacrifice Ill-Gotten Inheritance: It deals 4 damage to target opponent and you gain 4 life.

Citadel of Pain

At the beginning of each player's end step, Citadel of Pain deals X damage to that player, where X is the number of untapped lands they control.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Arcane Signet

Pain Magnification

Whenever an opponent is dealt 3 or more damage by a single source, that player discards a card.

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Rakdos Locket

{T}: Add {B} or {R}.
{B/R}{B/R}{B/R}{B/R}, {T}, Sacrifice Rakdos Locket: Draw two cards.

Rain of Gore

If a spell or ability would cause its controller to gain life, that player loses that much life instead.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Sin Prodder

Menace
At the beginning of your upkeep, reveal the top card of your library. Any opponent may have you put that card into your graveyard. If a player does, Sin Prodder deals damage to that player equal to that card's mana value. Otherwise, put that card into your hand.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

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.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Revel in Riches

Whenever a creature an opponent controls dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.

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.