Rhystic Cave

{T}: Choose a color. Add one mana of that color unless any player pays {1}. Activate only as an instant.

Chaotic Backlash

Chaotic Backlash deals damage to target player equal to twice the number of white and/or blue permanents they control.

Illusionary Mask

{X}: You may choose a creature card in your hand whose mana cost could be paid by some amount of, or all of, the mana you spent on {X}. If you do, you may cast that card face down as a 2/2 creature spell without paying its mana cost. If the creature that spell becomes as it resolves has not been turned face up and would assign or deal damage, be dealt damage, or become tapped, instead it's turned face up and assigns or deals damage, is dealt damage, or becomes tapped. Activate only as a sorcery.

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.)

Mask of Avacyn

Equipped creature gets +1/+2 and has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {3}

Tyrant's Machine

Goblin Bomb

At the beginning of your upkeep, you may flip a coin. If you win the flip, put a fuse counter on Goblin Bomb. If you lose the flip, remove a fuse counter from Goblin Bomb.
Remove five fuse counters from Goblin Bomb and sacrifice it: It deals 20 damage to target player or planeswalker.

Goblin Goon

Goblin Goon can't attack unless you control more creatures than defending player.
Goblin Goon can't block unless you control more creatures than attacking player.

Soldier of Fortune

{R}, {T}: Target player shuffles their library.

Mishra's War Machine

Banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)
At the beginning of your upkeep, Mishra's War Machine deals 3 damage to you unless you discard a card. If Mishra's War Machine deals damage to you this way, tap it.

The Brute

Enchant creature
Enchanted creature gets +1/+0.
{R}{R}{R}: Regenerate enchanted creature.

Mizzium Tank

Trample
Whenever you cast a noncreature spell, Mizzium Tank becomes an artifact creature and gets +1/+1 until end of turn.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Ratchet Bomb

{T}: Put a charge counter on Ratchet Bomb.
{T}, Sacrifice Ratchet Bomb: Destroy each nonland permanent with mana value equal to the number of charge counters on Ratchet Bomb.

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.

Bomb Squad

{T}: Put a fuse counter on target creature.
At the beginning of your upkeep, put a fuse counter on each creature with a fuse counter on it.
Whenever a creature has four or more fuse counters on it, remove all fuse counters from it and destroy it. That creature deals 4 damage to its controller.

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Tunnel Ignus

Whenever a land enters under an opponent's control, if that player had another land enter the battlefield under their control this turn, Tunnel Ignus deals 3 damage to that player.

Omen Machine

Players can't draw cards.
At the beginning of each player's draw step, that player exiles the top card of their library. If it's a land card, the player puts it onto the battlefield. Otherwise, the player casts it without paying its mana cost if able.

Keldon Firebombers

When Keldon Firebombers enters, each player sacrifices all lands they control except for three.

Proteus Machine

Morph {0} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Proteus Machine is turned face up, it becomes the creature type of your choice. (This effect lasts indefinitely.)

Citadel of Pain

At the beginning of each player's end step, Citadel of Pain deals X damage to that player, where X is the number of untapped lands they control.

Crown-Hunter Hireling

When Crown-Hunter Hireling enters, you become the monarch.
Crown-Hunter Hireling can't attack unless defending player is the monarch.

Thran War Machine

Echo {4} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
Thran War Machine attacks each combat if able.

Caverns of Despair

No more than two creatures can attack each combat.
No more than two creatures can block each combat.

Peregrine Mask

Equipped creature has defender, flying, and first strike.
Equip {2}

Uba Mask

If a player would draw a card, that player exiles that card face up instead.
Each player may play lands and cast spells from among cards they exiled with Uba Mask this turn.

Feedback Bolt

Feedback Bolt deals damage to target player or planeswalker equal to the number of artifacts you control.

Lightning Greaves

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

Rolling Temblor

Rolling Temblor deals 2 damage to each creature without flying.
Flashback {4}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Brothers Yamazaki

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
If there are exactly two permanents named Brothers Yamazaki on the battlefield, the "legend rule" doesn't apply to them.
Each other creature named Brothers Yamazaki gets +2/+2 and has haste.

Kamahl, Pit Fighter

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}: Kamahl, Pit Fighter deals 3 damage to any target.

Parallectric Feedback

Parallectric Feedback deals damage to target spell's controller equal to that spell's mana value.

Goblin Machinist

{2}{R}: Reveal cards from the top of your library until you reveal a nonland card. Goblin Machinist gets +X/+0 until end of turn, where X is that card's mana value. Put the revealed cards on the bottom of your library in any order.

Panic Spellbomb

{T}, Sacrifice Panic Spellbomb: Target creature can't block this turn.
When Panic Spellbomb is put into a graveyard from the battlefield, you may pay {R}. If you do, draw a card.

Sell-Sword Brute

When Sell-Sword Brute dies, it deals 2 damage to you.

Cave People

Whenever Cave People attacks, it gets +1/-2 until end of turn.
{1}{R}{R}, {T}: Target creature gains mountainwalk until end of turn. (It can't be blocked as long as defending player controls a Mountain.)

Desperate Gambit

Choose a source you control and flip a coin. If you win the flip, the next time that source would deal damage this turn, it deals double that damage instead. If you lose the flip, the next time it would deal damage this turn, prevent that damage.

Mask of Intolerance

At the beginning of each player's upkeep, if there are four or more basic land types among lands that player controls, Mask of Intolerance deals 3 damage to that player.

Rogue Skycaptain

Flying
At the beginning of your upkeep, put a wage counter on Rogue Skycaptain. You may pay {2} for each wage counter on it. If you don't, remove all wage counters from Rogue Skycaptain and an opponent gains control of it.

Brothers of Fire

{1}{R}{R}: Brothers of Fire deals 1 damage to any target and 1 damage to you.

Rakdos Pit Dragon

{R}{R}: Rakdos Pit Dragon gains flying until end of turn.
{R}: Rakdos Pit Dragon gets +1/+0 until end of turn.
Hellbent — Rakdos Pit Dragon has double strike as long as you have no cards in hand.

Bone Mask

{2}, {T}: The next time a source of your choice would deal damage to you this turn, prevent that damage. Exile cards from the top of your library equal to the damage prevented this way.

Dragon Mask

{3}, {T}: Target creature you control gets +2/+2 until end of turn. Return it to its owner's hand at the beginning of the next end step. (Return it only if it's on the battlefield.)

Mask of Immolation

When Mask of Immolation enters, create a 1/1 red Elemental creature token, then attach Mask of Immolation to it.
Equipped creature has "Sacrifice this creature: It deals 1 damage to any target."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Pyrite Spellbomb

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

Smoldering Spires

Smoldering Spires enters tapped.
When Smoldering Spires enters, target creature can't block this turn.
{T}: Add {R}.

Zoetic Cavern

{T}: Add {C}.
Morph {2} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Farsight Mask

Whenever a source an opponent controls deals damage to you, if Farsight Mask is untapped, you may draw a card.

Time Bomb

At the beginning of your upkeep, put a time counter on Time Bomb.
{1}, {T}, Sacrifice Time Bomb: Time Bomb deals damage equal to the number of time counters on it to each creature and each player.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Smoldering Crater

Smoldering Crater enters tapped.
{T}: Add {R}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Fractured Loyalty

Enchant creature
Whenever enchanted creature becomes the target of a spell or ability, that spell or ability's controller gains control of that creature. (This effect lasts indefinitely.)

Fiery Bombardment

Chroma — {2}, Sacrifice a creature: Fiery Bombardment deals damage to any target equal to the number of red mana symbols in the sacrificed creature's mana cost.

Moggcatcher

{3}, {T}: Search your library for a Goblin permanent card, put it onto the battlefield, then shuffle.

Nemesis Mask

All creatures able to block equipped creature do so.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Invasion Plans

All creatures block each combat if able.
The attacking player chooses how each creature blocks each combat.

Rolling Earthquake

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

Sorcerer's Strongbox

{2}, {T}: Flip a coin. If you win the flip, sacrifice Sorcerer's Strongbox and draw three cards.

Goblin Caves

Enchant land
As long as enchanted land is a basic Mountain, Goblin creatures get +0/+2.

Battle Strain

Whenever a creature blocks, Battle Strain deals 1 damage to that creature's controller.

Stronghold Gambit

Each player chooses a card in their hand. Then each player reveals their chosen card. The owner of each creature card revealed this way with the lowest mana value puts it onto the battlefield.