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.

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.

Mana Vault

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

Gratuitous Violence

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

Magus of the Moon

Blasphemous Act

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

Pristine Talisman

Prismatic Lens

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

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.)

Shattering Spree

Replicate {R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Destroy target artifact.

Fortune Thief

Damage that would reduce your life total to less than 1 reduces it to 1 instead.
Morph {R}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Defense Grid

Each spell costs {3} more to cast except during its controller's turn.

Torch Courier

Haste
Sacrifice Torch Courier: Another target creature gains haste until end of turn.

Scrying Sheets

{T}: Add {C}.
{1}{S}, {T}: Look at the top card of your library. If that card is snow, you may reveal it and put it into your hand. ({S} can be paid with one mana from a snow source.)

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Heartless Hidetsugu

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

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Lich's Mirror

If you would lose the game, instead shuffle your hand, your graveyard, and all permanents you own into your library, then draw seven cards and your life total becomes 20.

Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

Overblaze

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.
Splice onto Arcane {2}{R}{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.)

Ruby Medallion

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

Mind Stone

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

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.)

Arcane Signet

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

Mana Crypt

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

Mindmoil

Whenever you cast a spell, put the cards in your hand on the bottom of your library in any order, then draw that many cards.

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.")

Blood Moon

Rampaging Ferocidon

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

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Browbeat

Any player may have Browbeat deal 5 damage to them. If no one does, target player draws three cards.

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}.

Ashling's Prerogative

As Ashling's Prerogative enters, choose odd or even. (Zero is even.)
Each creature with mana value of the chosen quality has haste.
Each creature without mana value of the chosen quality enters tapped.

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Rite of Flame

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

Coldsteel Heart

Coldsteel Heart enters tapped.
As Coldsteel Heart enters, choose a color.
{T}: Add one mana of the chosen color.

Pyroblast

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

Fire Diamond

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

Red Elemental Blast

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

Smoke

Players can't untap more than one creature during their untap steps.

Dark Sphere

{T}, Sacrifice Dark Sphere: The next time a source of your choice would deal damage to you this turn, prevent half that damage, rounded down.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Footfall Crater

Enchant land
Enchanted land has "{T}: Target creature gains trample and haste until end of turn."
Cycling {1} ({1}, Discard this card: Draw a card.)

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.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Mouth of Ronom

{T}: Add {C}.
{4}{S}, {T}, Sacrifice Mouth of Ronom: It deals 4 damage to target creature. ({S} can be paid with one mana from a snow source.)

Commander's Sphere

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

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.'"

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Cathartic Reunion

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

Lightning Greaves

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

Tormenting Voice

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

Crimson Wisps

Target creature becomes red and gains haste until end of turn. (It can attack and {T} this turn.)
Draw a card.

Sol Ring

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.)

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Crawlspace

No more than two creatures can attack you each combat.

Furnace of Rath

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

Wheel of Fortune

Each player discards their hand, then draws seven cards.

Ensnaring Bridge

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

Snow-Covered Mountain

Seething Song

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)