Hedron Matrix

Equipped creature gets +X/+X, where X is its mana value.
Equip {4}

Scrabbling Claws

{T}: Target player exiles a card from their graveyard.
{1}, Sacrifice Scrabbling Claws: Exile target card from a graveyard. Draw a card.

Downhill Charge

You may sacrifice a Mountain rather than pay this spell's mana cost.
Target creature gets +X/+0 until end of turn, where X is the number of Mountains you control.

Burning Anger

Enchant creature
Enchanted creature has "{T}: This creature deals damage equal to its power to any target."

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Heirloom Blade

Equipped creature gets +3/+1.
Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order.
Equip {1}

Hero's Blade

Equipped creature gets +3/+2.
Whenever a legendary creature you control enters, you may attach Hero's Blade to it.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Ornithopter

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}.

Rapacious Dragon

Flying
When Rapacious Dragon enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sarkhan's Triumph

Search your library for a Dragon creature card, reveal it, put it into your hand, then shuffle.

Reckless Charge

Target creature gets +3/+0 and gains haste until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.")

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.

Abrade

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

Fire Diamond

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

Infuriate

Target creature gets +3/+2 until end of turn.

Alena, Kessig Trapper

First strike
{T}: Add an amount of {R} equal to the greatest power among creatures you control that entered this turn.
Partner (You can have two commanders if both have partner.)

Iron Myr

Lava Axe

Lava Axe deals 5 damage to target player or planeswalker.

Crucible of Fire

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Screaming Fury

Target creature gets +5/+0 and gains haste until end of turn.

Spinerock Knoll

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Spinerock Knoll enters tapped.
{T}: Add {R}.
{R}, {T}: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.

Wine of Blood and Iron

{4}: Target creature gets +X/+0 until end of turn, where X is its power. Sacrifice Wine of Blood and Iron at the beginning of the next end step.

Grafted Wargear

Equipped creature gets +3/+2.
Whenever Grafted Wargear becomes unattached from a permanent, sacrifice that permanent.
Equip {0} ({0}: Attach to target creature you control. Equip only as a sorcery.)

Catalyst Elemental

Sacrifice Catalyst Elemental: Add {R}{R}.

Uncaged Fury

Target creature gets +1/+1 and gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Goldspan Dragon

Flying, haste
Whenever Goldspan Dragon attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.

Ornithopter of Paradise

Dragon's Hoard

Whenever a Dragon you control enters, put a gold counter on Dragon's Hoard.
{T}, Remove a gold counter from Dragon's Hoard: Draw a card.
{T}: Add one mana of any color.

Lavabrink Floodgates

{T}: Add {R}{R}.
At the beginning of each player's upkeep, that player may put a doom counter on Lavabrink Floodgates or remove a doom counter from it. Then if it has three or more doom counters on it, sacrifice Lavabrink Floodgates. When you do, it deals 6 damage to each creature.

Mana Geyser

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

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.)

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.

Seething Song

Unleash Fury

Double the power of target creature until end of turn.

Retreat to Valakut

Landfall — Whenever a land you control enters, choose one —
• Target creature gets +2/+0 until end of turn.
• Target creature can't block this turn.

Sudden Breakthrough

Target creature gets +2/+0 and gains first strike until end of turn.
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ring of Valkas

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

Pyretic Ritual

Braid of Fire

Cumulative upkeep—Add {R}. (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.)

Forgotten Cave

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

Dragonlord's Servant

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

Dragonmaster Outcast

At the beginning of your upkeep, if you control six or more lands, create a 5/5 red Dragon creature token with flying.

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.

Gravitic Punch

Target creature you control deals damage equal to its power to target player.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Furious Rise

At the beginning of your end step, if you control a creature with power 4 or greater, exile the top card of your library. You may play that card until you exile another card with Furious Rise.

Hoard-Smelter Dragon

Flying
{3}{R}: Destroy target artifact. Hoard-Smelter Dragon gets +X/+0 until end of turn, where X is that artifact's mana value.

Hoarding Dragon

Flying
When Hoarding Dragon enters, you may search your library for an artifact card, exile it, then shuffle.
When Hoarding Dragon dies, you may put the exiled card into its owner's hand.

Mountain

Claim the Firstborn

Gain control of target creature with mana value 3 or less until end of turn. Untap that creature. It gains haste until end of turn.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Soul's Fire

Target creature you control deals damage equal to its power to any target.

Smelt

Inferno of the Star Mounts

This spell can't be countered.
Flying, haste
{R}: Inferno of the Star Mounts gets +1/+0 until end of turn. When its power becomes 20 this way, it deals 20 damage to any target.

Sol Ring

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.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Vessel of Volatility

{1}{R}, Sacrifice Vessel of Volatility: Add {R}{R}{R}{R}.

Thrill of Possibility

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

Samut's Sprint

Target creature gets +2/+1 and gains haste until end of turn. Scry 1.

Brass's Bounty

For each land you control, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Khalni Gem

When Khalni Gem enters, return two lands you control to their owner's hand.
{T}: Add two mana of any one color.

Tormenting Voice

Soulbright Flamekin

{2}: Target creature gains trample until end of turn. If this is the third time this ability has resolved this turn, you may add {R}{R}{R}{R}{R}{R}{R}{R}.

Rush of Blood

Target creature gets +X/+0 until end of turn, where X is its power.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Ruby Medallion

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

Titan's Strength

Target creature gets +3/+1 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Trove of Temptation

Each opponent must attack you or a planeswalker you control with at least one creature each combat if able.
At the beginning of your end step, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Brute Force

Target creature gets +3/+3 until end of turn.

Brute Strength

Target creature gets +3/+1 and gains trample until end of turn.

Hoarding Ogre

Whenever Hoarding Ogre attacks, roll a d20.
1—9 | Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
10—19 | Create two Treasure tokens.
20 | Create three Treasure tokens.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Irencrag Feat

Add seven {R}. You can cast only one more spell this turn.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Cathartic Reunion

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

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.