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.)

Mana Geyser

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

Snow-Covered Mountain

Kozilek, Butcher of Truth

When you cast this spell, draw four cards.
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents of their choice.)
When Kozilek is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Racecourse Fury

Enchant land
Enchanted land has "{T}: Target creature gains haste until end of turn."

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 this Equipment becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Anger of the Gods

Anger of the Gods deals 3 damage to each creature. If a creature dealt damage this way would die this turn, exile it instead.

Goblin Chieftain

Haste (This creature can attack and {T} as soon as it comes under your control.)
Other Goblin creatures you control get +1/+1 and have haste.

Endless Atlas

{2}, {T}: Draw a card. Activate only if you control three or more lands with the same name.

Pyretic Ritual

Tormenting Voice

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

Goblin Trashmaster

Other Goblins you control get +1/+1.
Sacrifice a Goblin: Destroy target artifact.

Shifting Shadow

Enchant creature
Enchanted creature has haste and "At the beginning of your upkeep, destroy this creature. Reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and attach Shifting Shadow to it, then put all other cards revealed this way on the bottom of your library in a random order."

Ulamog, the Infinite Gyre

When you cast this spell, destroy target permanent.
Indestructible
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents of their choice.)
When Ulamog is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Thran Dynamo

Indomitable Creativity

Destroy X target artifacts and/or creatures. For each permanent destroyed this way, its controller reveals cards from the top of their library until an artifact or creature card is revealed and exiles that card. Those players put the exiled cards onto the battlefield, then shuffle.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Sword of Feast and Famine

Equipped creature gets +2/+2 and has protection from black and from green.
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control.
Equip {2}

Jaya Ballard

+1: Add {R}{R}{R}. Spend this mana only to cast instant or sorcery spells.
+1: Discard up to three cards, then draw that many cards.
−8: You get an emblem with "You may cast instant and sorcery spells from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead."

Mikokoro, Center of the Sea

{T}: Add {C}.
{2}, {T}: Each player draws a card.

Gilded Lotus

Kher Keep

{T}: Add {C}.
{1}{R}, {T}: Create a 0/1 red Kobold creature token named Kobolds of Kher Keep.

Blasphemous Act

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

Warping Wail

({C} represents colorless mana.)
Choose one —
• Exile target creature with power or toughness 1 or less.
• Counter target sorcery spell.
• Create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this token: Add {C}."

Beetleback Chief

When this creature enters, create two 1/1 red Goblin creature tokens.

Ruination

All Is Dust

Each player sacrifices all permanents they control that are one or more colors.

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.")

Thrill of Possibility

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Tuktuk the Explorer

Haste
When Tuktuk the Explorer dies, create Tuktuk the Returned, a legendary 5/5 colorless Goblin Golem artifact creature token.

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.

Need for Speed

Sacrifice a land: Target creature gains haste until end of turn.

Hedron Archive

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

Fork

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

Tectonic Reformation

Each land card in your hand has cycling {R}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Smoke

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

Blood Moon

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Abrade

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

Divergent Transformations

Undaunted (This spell costs {1} less to cast for each opponent.)
Exile two target creatures. For each of those creatures, its controller reveals cards from the top of their library until they reveal a creature card, puts that card onto the battlefield, then shuffles the rest into their library.

Red Elemental Blast

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

Goblin King

Other Goblins get +1/+1 and have mountainwalk.

Chandra, Flamecaller

+1: Create two 3/1 red Elemental creature tokens with haste. Exile them at the beginning of the next end step.
0: Discard all the cards in your hand, then draw that many cards plus one.
−X: Chandra deals X damage to each creature.

Stolen Strategy

At the beginning of your upkeep, exile the top card of each opponent's library. Until end of turn, you may cast spells from among those exiled cards, and you may spend mana as though it were mana of any color to cast those spells.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Ruby Medallion

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

Cathartic Reunion

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

Price of Glory

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

Blightsteel Colossus

Trample, infect, indestructible
If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Reality Scramble

Put target permanent you own on the bottom of your library. Reveal cards from the top of your library until you reveal a card that shares a card type with that permanent. Put that card onto the battlefield and the rest on the bottom of your library in a random order.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Sol Ring

Gamble

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

Pyroblast

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

Lukka, Coppercoat Outcast

+1: Exile the top three cards of your library. Creature cards exiled this way gain "You may cast this card from exile as long as you control a Lukka planeswalker."
−2: Exile target creature you control, then reveal cards from the top of your library until you reveal a creature card with greater mana value. Put that card onto the battlefield and the rest on the bottom of your library in a random order.
−7: Each creature you control deals damage equal to its power to each opponent.

Reverberate

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

Stranglehold

Your opponents can't search libraries.
If an opponent would begin an extra turn, that player skips that turn instead.

Reforge the Soul

Each player discards their hand, then draws seven cards.
Miracle {1}{R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Seething Song

Ghitu Encampment

This land enters tapped.
{T}: Add {R}.
{1}{R}: This land becomes a 2/1 red Warrior creature with first strike until end of turn. It's still a land. (It deals combat damage before creatures without first strike.)

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.'"

Mishra's Factory

{T}: Add {C}.
{1}: This land becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

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.)

Wild Guess

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Argentum Armor

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip {6}