Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Arcane Signet

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

Plains

Seer's Vision

Your opponents play with their hands revealed.
Sacrifice this enchantment: Look at target player's hand and choose a card from it. That player discards that card. Activate only as a sorcery.

Nightveil Specter

Flying
Whenever this creature deals combat damage to a player, that player exiles the top card of their library.
You may play lands and cast spells from among cards exiled with this creature.

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Control Magic

Enchant creature
You control enchanted creature.

Firemind Vessel

This artifact enters tapped.
{T}: Add two mana of different colors.

Sen Triplets

At the beginning of your upkeep, choose target opponent. This turn, that player can't cast spells or activate abilities and plays with their hand revealed. You may play lands and cast spells from that player's hand this turn.

Isochron Scepter

Imprint — When this artifact enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

The Eternity Elevator

{T}: Add {C}{C}{C}.
Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery.)
20+ | {T}: Add X mana of any one color, where X is the number of charge counters on The Eternity Elevator.

Xanathar, Guild Kingpin

At the beginning of your upkeep, choose target opponent. Until end of turn, that player can't cast spells, you may look at the top card of their library any time, you may play the top card of their library, and you may spend mana as though it were mana of any color to cast spells this way.

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Siphon Insight

Look at the top two cards of target opponent's library. Exile one of them face down and put the other on the bottom of that library. You may play the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.
Flashback {1}{U}{B}

Paradox Haze

Enchant player
At the beginning of enchanted player's first upkeep each turn, that player gets an additional upkeep step after this step.

Praetor's Grasp

Search target opponent's library for a card and exile it face down. Then that player shuffles. You may play that card for as long as it remains exiled.

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.

Skyclave Relic

Kicker {3}
Indestructible
When this artifact enters, if it was kicked, create two tapped tokens that are copies of this artifact.
{T}: Add one mana of any color.

Omniscience

You may cast spells from your hand without paying their mana costs.

Swamp

Replicating Ring

{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on this artifact. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."

Thieving Varmint

Deathtouch, lifelink
{T}, Pay 1 life: Add two mana of any one color. Spend this mana only to cast spells you don't own.

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Acquire

Search target opponent's library for an artifact card and put that card onto the battlefield under your control. Then that player shuffles.

Crawlspace

No more than two creatures can attack you each combat.

Cunning Rhetoric

Whenever an opponent attacks you and/or one or more planeswalkers you control, exile the top card of that player's library. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.

Mirrormade

You may have this enchantment enter as a copy of any artifact or enchantment on the battlefield.

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Counterspell

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Relic of Legends

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

Command Tower

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Shadow of the Second Sun

Enchant player
At the beginning of each of enchanted player's postcombat main phases, there is an additional beginning phase after this phase. (The end step happens after the added untap, upkeep, and draw steps.)

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Tasha, the Witch Queen

Whenever you cast a spell you don't own, create a 3/3 black Demon creature token.
+1: Draw a card. For each opponent, exile up to one target instant or sorcery card from that player's graveyard and put a page counter on it.
−3: You may cast a spell from among cards in exile with page counters on them without paying its mana cost.
Tasha, the Witch Queen can be your commander.

Treachery

Enchant creature
When this Aura enters, untap up to five lands.
You control enchanted creature.

Mana Geode

When this artifact enters, scry 1.
{T}: Add one mana of any color.

Render Silent

Counter target spell. Its controller can't cast spells this turn.

Mind's Dilation

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

God-Pharaoh's Statue

Spells your opponents cast cost {2} more to cast.
At the beginning of your end step, each opponent loses 1 life.

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for them.)

Empress Galina

{U}{U}, {T}: Gain control of target legendary permanent. (This effect lasts indefinitely.)

Manalith

Thief of Sanity

Flying
Whenever this creature deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Nihiloor

When Nihiloor enters, for each opponent, tap up to one untapped creature you control. When you do, gain control of target creature that player controls with power less than or equal to the tapped creature's power for as long as you control Nihiloor.
Whenever you attack with a creature an opponent owns, you gain 2 life and that player loses 2 life.

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Sphere of Safety

Creatures can't attack you or planeswalkers you control unless their controller pays {X} for each of those creatures, where X is the number of enchantments you control.

Aura of Silence

Artifact and enchantment spells your opponents cast cost {2} more to cast.
Sacrifice this enchantment: Destroy target artifact or enchantment.

As Foretold

At the beginning of your upkeep, put a time counter on this enchantment.
Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less, where X is the number of time counters on this enchantment.

Bribery

Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Thran Dynamo

Blind Obedience

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Artifacts and creatures your opponents control enter tapped.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Fatespinner

At the beginning of each opponent's upkeep, that player chooses draw step, main phase, or combat phase. The player skips each instance of the chosen step or phase this turn.

Sol Ring

Gilded Drake

Flying
When this creature enters, exchange control of this creature and up to one target creature an opponent controls. If you don't or can't make an exchange, sacrifice this creature. This ability still resolves if its target becomes illegal.

Gilded Lotus

Corrupted Conscience

Enchant creature
You control enchanted creature.
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Staff of Eden, Vault's Key

When Staff of Eden enters, put target legendary permanent card not named Staff of Eden, Vault's Key from a graveyard onto the battlefield under your control.
{T}: Draw a card for each permanent you control but don't own.

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Hostage Taker

When this creature enters, exile another target creature or artifact until this creature leaves the battlefield. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Grafdigger's Cage

Creature cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.

Fellwar Stone

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

Exotic Orchard

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Island

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Lightning Greaves

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

Negate

Mind Control

Arvinox, the Mind Flail

Arvinox isn't a creature unless you control three or more permanents you don't own.
At the beginning of your end step, exile the bottom card of each opponent's library face down. For as long as those cards remain exiled, you may look at them, you may cast permanent spells from among them, and you may spend mana as though it were mana of any color to cast those spells.

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Court of Locthwain

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, exile the top card of target opponent's library. You may play that card for as long as it remains exiled, and mana of any type can be spent to cast it. If you're the monarch, until end of turn, you may cast a spell from among cards exiled with this enchantment without paying its mana cost.

Telepathy

Your opponents play with their hands revealed.

Arcane Sanctum

This land enters tapped.
{T}: Add {W}, {U}, or {B}.

Hall of Heliod's Generosity

{T}: Add {C}.
{1}{W}, {T}: Put target enchantment card from your graveyard on top of your library.