Fiendish Duo

First strike
If a source would deal damage to an opponent, it deals double that damage to that player instead.

Wojek Embermage

Radiance — {T}: Wojek Embermage deals 1 damage to target creature and each other creature that shares a color with it.

Jaya, Venerated Firemage

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.
−2: Jaya, Venerated Firemage deals 2 damage to any target.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Sculpting Steel

You may have Sculpting Steel enter as a copy of any artifact on the battlefield.

Slumbering Dragon

Flying
Slumbering Dragon can't attack or block unless it has five or more +1/+1 counters on it.
Whenever a creature attacks you or a planeswalker you control, put a +1/+1 counter on Slumbering Dragon.

Kyren Negotiations

Tap an untapped creature you control: Kyren Negotiations deals 1 damage to target player or planeswalker.

Zariel, Archduke of Avernus

+1: Creatures you control get +1/+0 and gain haste until end of turn.
0: Create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."
−6: You get an emblem with "At the end of the first combat phase on your turn, untap target creature you control. After this phase, there is an additional combat phase."

Outpost Siege

As Outpost Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons — Whenever a creature you control leaves the battlefield, Outpost Siege deals 1 damage to any target.

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.

Varchild, Betrayer of Kjeldor

Whenever Varchild, Betrayer of Kjeldor deals combat damage to a player, that player creates that many 1/1 red Survivor creature tokens.
Survivors your opponents control can't block, and they can't attack you or planeswalkers you control.
When Varchild leaves the battlefield, gain control of all Survivors.

Sol Talisman

Suspend 3—{1} (Rather than cast this card from your hand, pay {1} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
{T}: Add {C}{C}.

Circle of Flame

Whenever a creature without flying attacks you or a planeswalker you control, Circle of Flame deals 1 damage to that creature.

Kumano, Master Yamabushi

{1}{R}: Kumano, Master Yamabushi deals 1 damage to any target.
If a creature dealt damage by Kumano this turn would die, exile it instead.

Lobber Crew

Defender
{T}: Lobber Crew deals 1 damage to each opponent.
Whenever you cast a multicolored spell, untap Lobber Crew.

Fiery Confluence

Choose three. You may choose the same mode more than once.
• Fiery Confluence deals 1 damage to each creature.
• Fiery Confluence deals 2 damage to each opponent.
• Destroy target artifact.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Tok-Tok, Volcano Born

Protection from red
If a red source would deal damage to a player, it deals that much damage plus 1 to that player instead.

Akki Lavarunner

Haste
Whenever Akki Lavarunner deals damage to an opponent, flip it.

Akki Lavarunner // Tok-Tok, Volcano Born

Ancient Runes

At the beginning of each player's upkeep, Ancient Runes deals damage to that player equal to the number of artifacts they control.

Toralf's Hammer

Equipped creature has "{1}{R}, {T}, Unattach Toralf's Hammer: It deals 3 damage to any target. Return Toralf's Hammer to its owner's hand."
Equipped creature gets +3/+0 as long as it's legendary.
Equip {1}{R}

Toralf, God of Fury

Trample
Whenever a creature or planeswalker an opponent controls is dealt excess noncombat damage, Toralf deals damage equal to the excess to any target other than that permanent.

Toralf, God of Fury // Toralf's Hammer

Zo-Zu the Punisher

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

Rage Thrower

Whenever another creature dies, Rage Thrower deals 2 damage to target player or planeswalker.

Fires of Invention

You can cast spells only during your turn and you can cast no more than two spells each turn.
You may cast spells with mana value less than or equal to the number of lands you control without paying their mana costs.

Guttersnipe

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

Burn from Within

Burn from Within deals X damage to any target. If a creature is dealt damage this way, it loses indestructible until end of turn. If that creature would die this turn, exile it instead.

Mountain

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Manabarbs

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

Lightning-Rig Crew

{T}: Lightning-Rig Crew deals 1 damage to each opponent.
Whenever you cast a Pirate spell, untap Lightning-Rig Crew.

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.

Vicious Shadows

Whenever a creature dies, you may have Vicious Shadows deal damage to target player equal to the number of cards in that player's hand.

Double Vision

Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copy.

Zurzoth, Chaos Rider

Whenever an opponent draws their first card each turn, if it's not their turn, you create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."
Whenever one or more Devils you control attack one or more players, you and those players each draw a card, then discard a card at random.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

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.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Fire Ants

{T}: Fire Ants deals 1 damage to each other creature without flying.

Burning Earth

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

Chandra's Incinerator

This spell costs {X} less to cast, where X is the total amount of noncombat damage dealt to your opponents this turn.
Trample
Whenever a source you control deals noncombat damage to an opponent, Chandra's Incinerator deals that much damage to target creature or planeswalker that player controls.

Spiteful Prankster

During your turn, Spiteful Prankster has first strike.
Whenever another creature dies, Spiteful Prankster deals 1 damage to target player or planeswalker.

Detonate

Destroy target artifact with mana value X. It can't be regenerated. Detonate deals X damage to that artifact's controller.

Sol Ring

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.

Witty Roastmaster

Alliance — Whenever another creature you control enters, Witty Roastmaster deals 1 damage to each opponent.

Spellshock

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

Hissing Iguanar

Whenever another creature dies, you may have Hissing Iguanar deal 1 damage to target player or planeswalker.

Flame Rift

Flame Rift deals 4 damage to each player.

Barrage of Expendables

{R}, Sacrifice a creature: Barrage of Expendables deals 1 damage to any target.

Coalhauler Swine

Whenever Coalhauler Swine is dealt damage, it deals that much damage to each player.

Flameblade Angel

Flying
Whenever a source an opponent controls deals damage to you or a permanent you control, you may have Flameblade Angel deal 1 damage to that source's controller.

Kessig Flamebreather

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

Gratuitous Violence

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

Scab-Clan Berserker

Haste
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever an opponent casts a noncreature spell, if Scab-Clan Berserker is renowned, Scab-Clan Berserker deals 2 damage to that player.

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.

Rampaging Ferocidon

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

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.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Firecat Blitz

Create X 1/1 red Elemental Cat creature tokens with haste. Exile them at the beginning of the next end step.
Flashback—{R}{R}, Sacrifice X Mountains. (You may cast this card from your graveyard for its flashback cost. Then exile it.)