Sands of Time

Each player skips their untap step.
At the beginning of each player's upkeep, that player simultaneously untaps each tapped artifact, creature, and land they control and taps each untapped artifact, creature, and land they control.

Skullclamp

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

Darksteel Citadel

Decree of Annihilation

Exile all artifacts, creatures, and lands from the battlefield, all cards from all graveyards, and all cards from all hands.
Cycling {5}{R}{R} ({5}{R}{R}, Discard this card: Draw a card.)
When you cycle Decree of Annihilation, destroy all lands.

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Mountain

Grip of Chaos

Whenever a spell or ability is put onto the stack, if it has a single target, reselect its target at random. (Select from among all legal targets.)

Reverberate

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

Widespread Panic

Whenever a spell or ability causes its controller to shuffle their library, that player puts a card from their hand on top of their library.

Price of Glory

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

Meekstone

Creatures with power 3 or greater don't untap during their controllers' untap steps.

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.

Kher Keep

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

Scrambleverse

For each nonland permanent, choose a player at random. Then each player gains control of each permanent for which they were chosen. Untap those permanents.

War Elemental

When War Elemental enters, sacrifice it unless an opponent was dealt damage this turn.
Whenever an opponent is dealt damage, put that many +1/+1 counters on War Elemental.

Risky Move

At the beginning of each player's upkeep, that player gains control of Risky Move.
When you gain control of Risky Move from another player, choose a creature you control and an opponent. Flip a coin. If you lose the flip, that opponent gains control of that creature.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Sol Ring

Beetleback Chief

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

Chandra, the Firebrand

+1: Chandra, the Firebrand deals 1 damage to any target.
−2: When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
−6: Chandra, the Firebrand deals 6 damage to each of up to six targets.

Mana Clash

You and target opponent each flip a coin. Mana Clash deals 1 damage to each player whose coin comes up tails. Repeat this process until both players' coins come up heads on the same flip.

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Goblin Matron

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

Rummaging Goblin

Outpost Siege

As Outpost Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons — Whenever a creature you control leaves the battlefield, Outpost Siege deals 1 damage to any target.

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.

Brand

Gain control of all permanents you own. (This effect lasts indefinitely.)
Cycling {2} ({2}, Discard this card: Draw a card.)

Goblin Recruiter

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

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Confusion in the Ranks

Whenever an artifact, creature, or enchantment enters, its controller chooses target permanent another player controls that shares a card type with it. Exchange control of those permanents.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Fire Diamond

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

Jokulhaups

Destroy all artifacts, creatures, and lands. They can't be regenerated.

Arena of the Ancients

Legendary creatures don't untap during their controllers' untap steps.
When Arena of the Ancients enters, tap all legendary creatures.

Ruination

Genesis Chamber

Whenever a nontoken creature enters, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Game of Chaos

Flip a coin. If you win the flip, you gain 1 life and target opponent loses 1 life, and you decide whether to flip again. If you lose the flip, you lose 1 life and that opponent gains 1 life, and that player decides whether to flip again. Double the life stakes with each flip.

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.)

Aftershock

Destroy target artifact, creature, or land. Aftershock deals 3 damage to you.

Heat Stroke

At end of combat, destroy each creature that blocked or was blocked this turn.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Forgotten Cave

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

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Curse of Bloodletting

Enchant player
If a source would deal damage to enchanted player, it deals double that damage to that player instead.

Goblin Game

Each player hides at least one item, then all players reveal them simultaneously. Each player loses life equal to the number of items they revealed. The player who revealed the fewest items then loses half their life, rounded up. If two or more players are tied for fewest, each loses half their life, rounded up.

Possibility Storm

Whenever a player casts a spell from their hand, that player exiles it, then exiles cards from the top of their library until they exile a card that shares a card type with it. That player may cast that card without paying its mana cost. Then they put all cards exiled with Possibility Storm on the bottom of their library in a random order.

Goblin Warchief

Goblin spells you cast cost {1} less to cast.
Goblins you control have haste.

Illicit Auction

Each player may bid life for control of target creature. You start the bidding with a bid of 0. In turn order, each player may top the high bid. The bidding ends if the high bid stands. The high bidder loses life equal to the high bid and gains control of the creature. (This effect lasts indefinitely.)

Ruby Medallion

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

Mogg War Marshal

Echo {1}{R} (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.)
When Mogg War Marshal enters or dies, create a 1/1 red Goblin creature token.

Red Elemental Blast

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

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.

Norin the Wary

When a player casts a spell or a creature attacks, exile Norin the Wary. Return it to the battlefield under its owner's control at the beginning of the next end step.

Static Orb

As long as Static Orb is untapped, players can't untap more than two permanents during their untap steps.

Goblin Assassin

Whenever Goblin Assassin or another Goblin enters, each player flips a coin. Each player whose coin comes up tails sacrifices a creature of their choice.

Planar Chaos

At the beginning of your upkeep, flip a coin. If you lose the flip, sacrifice Planar Chaos.
Whenever a player casts a spell, that player flips a coin. If they lose the flip, counter that spell.

In the Web of War

Whenever a creature you control enters, it gets +2/+0 and gains haste until end of turn.

Tuktuk Scrapper

Whenever Tuktuk Scrapper or another Ally you control enters, you may destroy target artifact. If that artifact is put into a graveyard this way, Tuktuk Scrapper deals damage to that artifact's controller equal to the number of Allies you control.

Word of Seizing

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Untap target permanent and gain control of it until end of turn. It gains haste until end of turn.

Warp World

Each player shuffles all permanents they own into their library, then reveals that many cards from the top of their library. Each player puts all artifact, creature, and land cards revealed this way onto the battlefield, then does the same for enchantment cards, then puts all cards revealed this way that weren't put onto the battlefield on the bottom of their library.

Pandemonium

Whenever a creature enters, that creature's controller may have it deal damage equal to its power to any target of their choice.

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Honor-Worn Shaku

{T}: Add {C}.
Tap an untapped legendary permanent you control: Untap Honor-Worn Shaku.

Fiery Gambit

Flip a coin until you lose a flip or choose to stop flipping. If you lose a flip, Fiery Gambit has no effect. If you win one or more flips, Fiery Gambit deals 3 damage to target creature. If you win two or more flips, Fiery Gambit deals 6 damage to each opponent. If you win three or more flips, draw nine cards and untap all lands you control.

Firecat Blitz

Create X 1/1 red Elemental Cat creature tokens with haste. Exile them at the beginning of the next end step.
Flashback—{R}{R}, Sacrifice X Mountains. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Smoke

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

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Stingscourger

Echo {3}{R} (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.)
When Stingscourger enters, return target creature an opponent controls to its owner's hand.

Whims of the Fates

Starting with you, each player separates all permanents they control into three piles. Then each player chooses one of their piles at random and sacrifices those permanents. (Piles can be empty.)

Storage Matrix

As long as Storage Matrix is untapped, each player chooses artifact, creature, or land during their untap step. That player can untap only permanents of the chosen type this step.

Wild Ricochet

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