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.

Obliterate

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

Ashling the Pilgrim

{1}{R}: Put a +1/+1 counter on Ashling the Pilgrim. If this is the third time this ability has resolved this turn, remove all +1/+1 counters from Ashling the Pilgrim, and it deals that much damage to each creature and each player.

Sol Ring

Forgotten Cave

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

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Strip Mine

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

Chandra, Awakened Inferno

This spell can't be countered.
+2: Each opponent gets an emblem with "At the beginning of your upkeep, this emblem deals 1 damage to you."
−3: Chandra, Awakened Inferno deals 3 damage to each non-Elemental creature.
−X: Chandra, Awakened Inferno deals X damage to target creature or planeswalker. If a permanent dealt damage this way would die this turn, exile it instead.

Terminate

Destroy target creature. It can't be regenerated.

Terramorphic Expanse

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

Angrath, the Flame-Chained

+1: Each opponent discards a card and loses 2 life.
−3: Gain control of target creature until end of turn. Untap it. It gains haste until end of turn. Sacrifice it at the beginning of the next end step if it has mana value 3 or less.
−8: Each opponent loses life equal to the number of cards in their graveyard.

Bedevil

Destroy target artifact, creature, or planeswalker.

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.

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.

Glacial Chasm

Cumulative upkeep—Pay 2 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When Glacial Chasm enters, sacrifice a land.
Creatures you control can't attack.
Prevent all damage that would be dealt to you.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Exsanguinate

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

Swamp

Unstable Obelisk

{T}: Add {C}.
{7}, {T}, Sacrifice Unstable Obelisk: Destroy target permanent.

Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Zo-Zu the Punisher

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

Ankh of Mishra

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

Arcane Signet

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

Command Tower

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.

Bloodstained Mire

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

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.

Polluted Bonds

Whenever a land an opponent controls enters, that player loses 2 life and you gain 2 life.

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.

Chandra, Torch of Defiance

+1: Exile the top card of your library. You may cast that card. If you don't, Chandra, Torch of Defiance deals 2 damage to each opponent.
+1: Add {R}{R}.
−3: Chandra, Torch of Defiance deals 4 damage to target creature.
−7: You get an emblem with "Whenever you cast a spell, this emblem deals 5 damage to any target."

Smoldering Marsh

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

Rakdos Signet

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.

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 Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Palace Siege

As Palace Siege enters, 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.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Jet Medallion

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

Damnation

Destroy all creatures. They can't be regenerated.

Decree of Annihilation

Exile all artifacts, creatures, and lands from the battlefield, all cards from all graveyards, and all cards from all hands.
Cycling {5}{R}{R} ({5}{R}{R}, Discard this card: Draw a card.)
When you cycle Decree of Annihilation, destroy all lands.

Ruby Medallion

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

Mountain

Mind Stone

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

Murder

Starstorm

Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)

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."

Reliquary Tower

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

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.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

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}.

Bojuka Bog

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

Smoke

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

Temple of Malice

Temple of Malice enters tapped.
When Temple of Malice enters, scry 1.
{T}: Add {B} or {R}.

Last One Standing

Choose a creature at random, then destroy the rest.

Read the Bones

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

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.

Barren Moor

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

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.

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.

Kroxa, Titan of Death's Hunger

When Kroxa enters, sacrifice it unless it escaped.
Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Erebos, God of the Dead

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Your opponents can't gain life.
{1}{B}, Pay 2 life: Draw a card.

Blasphemous Act

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

Manabarbs

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

Necropotence

Skip your draw step.
Whenever you discard a card, exile that card from your graveyard.
Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Canyon Slough

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

Tainted Aether

Whenever a creature enters, its controller sacrifices a creature or land.

Solemn Simulacrum

When Solemn Simulacrum enters, 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.

Heartless Hidetsugu

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

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Phyrexian Arena

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

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Jokulhaups

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

Deadly Rollick

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

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Crimson Honor Guard

Trample
At the beginning of each player's end step, Crimson Honor Guard deals 4 damage to that player unless they control a commander.

Evolving Wilds

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

Indulgent Tormentor

Flying
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature or pays 3 life.

Bloodfell Caves

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

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.