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.

Zo-Zu the Punisher

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

Burning Earth

Whenever a player taps a nonbasic land for mana, Burning Earth deals 1 damage to that player.

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.

Tormenting Voice

As an additional cost to cast this spell, discard a card.
Draw two cards.

Blasphemous Act

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

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.

Heartless Hidetsugu

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

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Mana Geyser

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

Stigma Lasher

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever Stigma Lasher deals damage to a player, that player can't gain life for the rest of the game.

Fire Diamond

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

Manabarbs

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

Sun Droplet

Whenever you're dealt damage, put that many charge counters on Sun Droplet.
At the beginning of each upkeep, you may remove a charge counter from Sun Droplet. If you do, you gain 1 life.

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

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."

Chef's Kiss

Gain control of target spell that targets only a single permanent or player. Copy it, then reselect the targets at random for the spell and the copy. The new targets can't be you or a permanent you control.

Koth of the Hammer

+1: Untap target Mountain. It becomes a 4/4 red Elemental creature until end of turn. It's still a land.
−2: Add {R} for each Mountain you control.
−5: You get an emblem with "Mountains you control have '{T}: This land deals 1 damage to any target.'"

Obsidian Fireheart

{1}{R}{R}: Put a blaze counter on target land without a blaze counter on it. For as long as that land has a blaze counter on it, it has "At the beginning of your upkeep, this land deals 1 damage to you." (The land continues to burn after Obsidian Fireheart has left the battlefield.)

Embermaw Hellion

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
If another red source you control would deal damage to a permanent or player, it deals that much damage plus 1 to that permanent or player instead.

Neheb, Dreadhorde Champion

Trample
Whenever Neheb, Dreadhorde Champion deals combat damage to a player or planeswalker, you may discard any number of cards. If you do, draw that many cards and add that much {R}. Until end of turn, you don't lose this mana as steps and phases end.

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.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

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.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Seething Song

Ghirapur Orrery

Each player may play an additional land on each of their turns.
At the beginning of each player's upkeep, if that player has no cards in hand, that player draws three cards.

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

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.

Pyretic Ritual

Cemetery Gatekeeper

First strike
When Cemetery Gatekeeper enters, exile a card from a graveyard.
Whenever a player plays a land or casts a spell, if it shares a card type with the exiled card, Cemetery Gatekeeper deals 2 damage to that player.

Stoneshaker Shaman

At the beginning of each player's end step, that player sacrifices an untapped land of their choice.

Rampaging Ferocidon

Menace
Players can't gain life.
Whenever another creature enters, Rampaging Ferocidon deals 1 damage to that creature's controller.

Volcanic Fallout

This spell can't be countered.
Volcanic Fallout deals 2 damage to each creature and each player.

Spellshock

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

Earthquake

Earthquake deals X damage to each creature without flying 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.

Sol Ring

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Pyrostatic Pillar

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

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Ankh of Mishra

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

Acidic Soil

Acidic Soil deals damage to each player equal to the number of lands they control.

Dwarven Driller

{T}: Destroy target land unless its controller has Dwarven Driller deal 2 damage to them.

Gamble

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

Leyline Tyrant

Flying
You don't lose unspent red mana as steps and phases end.
When Leyline Tyrant dies, you may pay any amount of {R}. When you do, it deals that much damage to any target.

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.")

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.

Wild Ricochet

You may choose new targets for target instant or sorcery spell. Then copy that spell. You may choose new targets for the copy.

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Leyline of Combustion

If Leyline of Combustion is in your opening hand, you may begin the game with it on the battlefield.
Whenever you and/or at least one permanent you control becomes the target of a spell or ability an opponent controls, Leyline of Combustion deals 2 damage to that player.

Arcane Signet

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

Seismic Strike

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

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.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Court of Ire

When Court of Ire enters, you become the monarch.
At the beginning of your upkeep, Court of Ire deals 2 damage to any target. If you're the monarch, it deals 7 damage instead.