Cathartic Reunion

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

Rousing Refrain

Add {R} for each card in target opponent's hand. Until end of turn, you don't lose this mana as steps and phases end. Exile Rousing Refrain with three time counters on it.
Suspend 3—{1}{R} (Rather than cast this card from your hand, you may pay {1}{R} 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.)

Reiterate

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Copy target instant or sorcery spell. You may choose new targets for the copy.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Ensnaring Bridge

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

Wildfire Devils

When Wildfire Devils enters and at the beginning of your upkeep, choose a player at random. That player exiles an instant or sorcery card from their graveyard. Copy that card. You may cast the copy without paying its mana cost.

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.)

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

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.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

By Force

Arcane Signet

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

Temple of Power

(Transforms from Ojer Axonil, Deepest Might.)
{T}: Add {R}.
{2}{R}, {T}: Transform Temple of Power. Activate only if red sources you controlled dealt 4 or more noncombat damage this turn and only as a sorcery.

Ojer Axonil, Deepest Might

Trample
If a red source you control would deal an amount of noncombat damage less than Ojer Axonil's power to an opponent, that source deals damage equal to Ojer Axonil's power instead.
When Ojer Axonil dies, return it to the battlefield tapped and transformed under its owner's control.

Ojer Axonil, Deepest Might // Temple of Power

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Fiery Inscription

When Fiery Inscription enters, the Ring tempts you.
Whenever you cast an instant or sorcery spell, Fiery Inscription deals 2 damage to each opponent.

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.

Thrill of Possibility

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

Price of Progress

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

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Vulshok Sorcerer

Haste
{T}: Vulshok Sorcerer deals 1 damage to any target.

Tormenting Voice

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Deadeye Duelist

Reach
{1}, {T}: Deadeye Duelist deals 1 damage to target opponent.

Fire Diamond

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

Fire Servant

If a red instant or sorcery spell you control would deal damage, it deals double that damage instead.

Spikefield Cave

Spikefield Cave enters tapped.
{T}: Add {R}.

Spikefield Hazard

Spikefield Hazard deals 1 damage to any target. If a permanent dealt damage this way would die this turn, exile it instead.

Spikefield Hazard // Spikefield Cave

Mana Geyser

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

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.

Pyromancer's Goggles

{T}: Add {R}. When that mana is spent to cast a red instant or sorcery spell, copy that spell and you may choose new targets for the copy.

Thought Vessel

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

Mountain

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.")

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mogg Salvage

If an opponent controls an Island and you control a Mountain, you may cast this spell without paying its mana cost.
Destroy target artifact.

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Reverberate

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

Guttersnipe

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

Cave-In

You may exile a red card from your hand rather than pay this spell's mana cost.
Cave-In deals 2 damage to each creature and each player.

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

Worn Powerstone

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

Rolling Earthquake

Rolling Earthquake deals X damage to each creature without horsemanship and each player.

Cinder Pyromancer

{T}: Cinder Pyromancer deals 1 damage to target player or planeswalker.
Whenever you cast a red spell, you may untap Cinder Pyromancer.

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice Underworld Breach.

Blasphemous Act

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

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Dualcaster Mage

Flash
When Dualcaster Mage enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Roiling Vortex

At the beginning of each player's upkeep, Roiling Vortex deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Mind Stone

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

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

Breath of Darigaaz

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Breath of Darigaaz deals 1 damage to each creature without flying and each player. If this spell was kicked, it deals 4 damage to each creature without flying and each player instead.

Sol Ring

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Mizzix's Mastery

Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery.
Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Gilded Lotus

Pyretic Ritual

Volcanic Spray

Volcanic Spray deals 1 damage to each creature without flying and each player.
Flashback {1}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Volcanic Vision

Return target instant or sorcery card from your graveyard to your hand. Volcanic Vision deals damage equal to that card's mana value to each creature your opponents control. Exile Volcanic Vision.

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Acidic Soil

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

Firebrand Archer

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

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.

Dwarven Ruins

Dwarven Ruins enters tapped.
{T}: Add {R}.
{T}, Sacrifice Dwarven Ruins: Add {R}{R}.

Coalition Relic

{T}: Add one mana of any color.
{T}: Put a charge counter on Coalition Relic.
At the beginning of your first main phase, remove all charge counters from Coalition Relic. Add one mana of any color for each charge counter removed this way.