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.)

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Final Fortune

Take an extra turn after this one. At the beginning of that turn's end step, you lose the game.

Abrade

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

Gemstone Caverns

If this card is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

City of Traitors

When you play another land, sacrifice this land.
{T}: Add {C}{C}.

Ashnod's Altar

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Skirk Prospector

Defiler of Instinct

First strike
As an additional cost to cast red permanent spells, you may pay 2 life. Those spells cost {R} less to cast if you paid life this way. This effect reduces only the amount of red mana you pay.
Whenever you cast a red permanent spell, this creature deals 1 damage to any target.

Jeweled Lotus

{T}, Sacrifice this artifact: Add three mana of any one color. Spend this mana only to cast your commander.

_____ Goblin

When this creature enters, you may put a name sticker on it. Add {R} for each unique vowel on that sticker. (The vowels are A, E, I, O, U, and Y.)

Goblin Matron

When this creature enters, you may search your library for a Goblin card, reveal that card, put it into your hand, then shuffle.

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Mishra's Bauble

{T}, Sacrifice this artifact: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Pyrite Spellbomb

{R}, Sacrifice this artifact: It deals 2 damage to any target.
{1}, Sacrifice this artifact: Draw a card.

Treasonous Ogre

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Pay 3 life: Add {R}.

Chrome Mox

Imprint — When this artifact enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Goblin Recruiter

When this creature enters, search your library for any number of Goblin cards, reveal them, then shuffle and put those cards on top in any order.

Impulsive Pilferer

When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Encore {3}{R} ({3}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Ruby Medallion

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

Crimson Kobolds

Vexing Bauble

Whenever a player casts a spell, if no mana was spent to cast it, counter that spell.
{1}, {T}, Sacrifice this artifact: Draw a card.

Lion's Eye Diamond

Discard your hand, Sacrifice this artifact: Add three mana of any one color. Activate only as an instant.

Memnite

Ricochet Trap

If an opponent cast a blue spell this turn, you may pay {R} rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Dockside Extortionist

When this creature enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Harnfel, Horn of Bounty

Discard a card: Exile the top two cards of your library. You may play those cards this turn.

Birgi, God of Storytelling

Whenever you cast a spell, add {R}. Until end of turn, you don't lose this mana as steps and phases end.
Creatures you control can boast twice during each of your turns rather than once.

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Goblin Welder

{T}: Choose target artifact a player controls and target artifact card in that player's graveyard. If both targets are still legal as this ability resolves, that player simultaneously sacrifices the artifact and returns the artifact card to the battlefield.

Thermopod

{S}: This creature gains haste until end of turn. ({S} can be paid with one mana from a snow source.)
Sacrifice a creature: Add {R}.

Geosurge

Add {R}{R}{R}{R}{R}{R}{R}. Spend this mana only to cast artifact or creature spells.

Red Elemental Blast

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

Last Chance

Seething Song

Simian Spirit Guide

Demand Answers

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

Goblin Engineer

When this creature enters, you may search your library for an artifact card, put it into your graveyard, then shuffle.
{R}, {T}, Sacrifice an artifact: Return target artifact card with mana value 3 or less from your graveyard to the battlefield.

Urza's Bauble

{T}, Sacrifice this artifact: Look at a card at random in target player's hand. You draw a card at the beginning of the next turn's upkeep.

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Grim Monolith

This artifact doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{4}: Untap this artifact.

Overmaster

The next instant or sorcery spell you cast this turn can't be countered.
Draw a card.

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.

Serum Powder

{T}: Add {C}.
Any time you could mulligan and this card is in your hand, you may exile all the cards from your hand, then draw that many cards. (You can do this in addition to taking mulligans.)

Lightning Bolt

Lightning Bolt deals 3 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.")

Runaway Steam-Kin

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

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Jeska, Thrice Reborn

Jeska enters with a loyalty counter on her for each time you've cast a commander from the command zone this game.
0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead.
−X: Jeska deals X damage to each of up to three targets.
Jeska, Thrice Reborn can be your commander.
Partner

Infernal Plunge

As an additional cost to cast this spell, sacrifice a creature.
Add {R}{R}{R}.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, this artifact deals 3 damage to you.
{T}: Add {C}{C}.

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.)

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice this land: Add {C}{C}.

Mountain

Vessel of Volatility

{1}{R}, Sacrifice this enchantment: Add {R}{R}{R}{R}.

Ragavan, Nimble Pilferer

Whenever Ragavan deals combat damage to a player, create a Treasure token and exile the top card of that player's library. Until end of turn, you may cast that card.
Dash {1}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Mana Vault

This artifact doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap this artifact.
At the beginning of your draw step, if this artifact is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Pyretic Ritual

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Sol Ring

Rite of Flame

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

Fork

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.

Kobolds of Kher Keep

Herigast, Erupting Nullkite

Emerge {6}{R}{R} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, you may exile your hand. If you do, draw three cards.
Flying
Each creature spell you cast has emerge. The emerge cost is equal to its mana cost.

Gamble

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

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Lotus Petal

{T}, Sacrifice this artifact: Add one mana of any color.

Reckless Barbarian

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Crookshank Kobolds

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

Reverberate

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

Mox Diamond

If this artifact would enter, you may discard a land card instead. If you do, put this artifact onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.

Chromatic Star

{1}, {T}, Sacrifice this artifact: Add one mana of any color.
When this artifact is put into a graveyard from the battlefield, draw a card.

Warrior's Oath

Flare of Duplication

You may sacrifice a nontoken red creature rather than pay this spell's mana cost.
Copy target instant or sorcery spell. You may choose new targets for the copy.

Highway Robbery

You may discard a card or sacrifice a land. If you do, draw two cards.
Plot {1}{R} (You may pay {1}{R} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Dargo, the Shipwrecker

As an additional cost to cast this spell, you may sacrifice any number of artifacts and/or creatures. This spell costs {2} less to cast for each permanent sacrificed this way and {2} less to cast for each other artifact or creature you've sacrificed this turn.
Trample
Partner (You can have two commanders if both have partner.)

Helm of Awakening

Imperial Recruiter

When this creature enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.