Blasphemous Act

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

Rakdos, Patron of Chaos

Flying, trample
At the beginning of your end step, target opponent may sacrifice two nonland, nontoken permanents of their choice. If they don't, you draw two cards.

Smoldering Marsh

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

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.

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.

Tainted Peak

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

Mountain

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.

Manabarbs

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

Tainted Remedy

If an opponent would gain life, that player loses that much life instead.

Polluted Bonds

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

Talisman of Indulgence

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

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Fires of Mount Doom

When Fires of Mount Doom enters, it deals 2 damage to target creature an opponent controls. Destroy all Equipment attached to that creature.
{2}{R}: Exile the top card of your library. You may play that card this turn. When you play a card this way, Fires of Mount Doom deals 2 damage to each player.

Painful Quandary

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

Feed the Swarm

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

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 of their choice.

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Phyrexian Arena

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

Exsanguinate

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

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.

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.)

Court of Ambition

When Court of Ambition enters, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

Fiery Emancipation

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

Disrupt Decorum

Goad all creatures you don't control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Temple of Malice

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {R}.

Arcane Signet

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

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

Mount Doom

{T}, Pay 1 life: Add {B} or {R}.
{1}{B}{R}, {T}: Mount Doom deals 1 damage to each opponent.
{5}{B}{R}, {T}, Sacrifice Mount Doom and a legendary artifact: Choose up to two creatures, then destroy the rest. Activate only as a sorcery.

Price of Glory

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

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.

Deadly Rollick

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

Command Tower

Smoke

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

Syphon Mind

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

Fanatic of Mogis

When Fanatic of Mogis enters, it deals damage to each opponent equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)

Blood for the Blood God!

This spell costs {1} less to cast for each creature that died this turn.
Discard your hand, then draw eight cards. Blood for the Blood God! deals 8 damage to each opponent. Exile Blood for the Blood God!

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.

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.

Pyrostatic Pillar

Whenever a player casts a spell with mana value 3 or less, Pyrostatic Pillar deals 2 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.

Crawlspace

No more than two creatures can attack you each combat.

Rakdos Signet

Ensnaring Bridge

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

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.

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.

Glacial Crevasses

Sacrifice a snow Mountain: Prevent all combat damage that would be dealt this turn.

Starstorm

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

Dingus Staff

Whenever a creature dies, Dingus Staff deals 2 damage to that creature's controller.

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.

Dreadbore

Sol Ring

No Mercy

Whenever a creature deals damage to you, destroy it.

Deadly Tempest

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

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your first main phase, add {B} for each charge counter on Black Market.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Wheel of Fortune

Each player discards their hand, then draws seven cards.

Expedition Map

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

Rakdos Carnarium

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

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Maddening Hex

Enchant player
Whenever enchanted player casts a noncreature spell, roll a d6. Maddening Hex deals damage to that player equal to the result. Then attach Maddening Hex to another one of your opponents chosen at random.

Koth, Fire of Resistance

+2: Search your library for a basic Mountain card, reveal it, put it into your hand, then shuffle.
−3: Koth, Fire of Resistance deals damage to target creature equal to the number of Mountains you control.
−7: You get an emblem with "Whenever a Mountain you control enters, this emblem deals 4 damage to any target."

The Nipton Lottery

Choose a creature at random. You gain control of that creature until end of turn. Untap it. It gains haste until end of turn. Then destroy all other creatures.

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.)

Mana Geyser

Add {R} for each tapped land your opponents control.

Foreboding Ruins

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

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Swamp

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Tainted Aether

Whenever a creature enters, its controller sacrifices a creature or land of their choice.

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.

Repercussion

Whenever a creature is dealt damage, Repercussion deals that much damage to that creature's controller.

Lethal Vapors

Whenever a creature enters, destroy it.
{0}: Destroy Lethal Vapors. You skip your next turn. Any player may activate this ability.