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.

Bribery

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

Damnation

Destroy all creatures. They can't be regenerated.

Counterspell

Hurl Through Hell

Exile target creature. Until the end of your next turn, you may cast that card and you may spend mana as though it were mana of any color to cast that spell.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Spelltwine

Exile target instant or sorcery card from your graveyard and target instant or sorcery card from an opponent's graveyard. Copy those cards. Cast the copies if able without paying their mana costs. Exile Spelltwine.

Fevered Suspicion

Each opponent exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among those nonland cards without paying their mana costs.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Blatant Thievery

For each opponent, gain control of target permanent that player controls.

Hostage Taker

When Hostage Taker enters, exile another target creature or artifact until Hostage Taker 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.

Fellwar Stone

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

Disrupt Decorum

Goad all creatures you don't control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Explore the Vastlands

Each player looks at the top five cards of their library and may reveal a land card and/or an instant or sorcery card from among them. Each player puts the cards they revealed this way into their hand and the rest on the bottom of their library in a random order. Each player gains 3 life.

Wandering Archaic

Whenever an opponent casts an instant or sorcery spell, they may pay {2}. If they don't, you may copy that spell. You may choose new targets for the copy.

Wandering Archaic // Explore the Vastlands

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

The Scarab God

At the beginning of your upkeep, each opponent loses X life and you scry X, where X is the number of Zombies you control.
{2}{U}{B}: Exile target creature card from a graveyard. Create a token that's a copy of it, except it's a 4/4 black Zombie.
When The Scarab God dies, return it to its owner's hand at the beginning of the next end step.

Bedevil

Destroy target artifact, creature, or planeswalker.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Agent of Treachery

When Agent of Treachery 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.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Sol Ring

Telepathy

Your opponents play with their hands revealed.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Dimir Signet

Arcane Signet

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

Gonti, Lord of Luxury

Deathtouch
When Gonti, Lord of Luxury enters, look at the top four cards of target opponent's library, exile one of them face down, then put the rest on the bottom of that library in a random order. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Mezzio Mugger

Whenever Mezzio Mugger attacks, exile the top card of each player's library. You may play those cards this turn, and you may spend mana as though it were mana of any color to cast those spells.
Blitz {2}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Heat Shimmer

Create a token that's a copy of target creature, except it has haste and "At the beginning of the end step, exile this permanent."

Stunt Double

Flash
You may have Stunt Double enter as a copy of any creature on the battlefield.

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.

Dire Fleet Daredevil

First strike
When Dire Fleet Daredevil enters, exile target instant or sorcery card from an opponent's graveyard. You may cast it this turn, and mana of any type can be spent to cast that spell. If that spell would be put into a graveyard, exile it instead.

Stolen Goods

Target opponent exiles cards from the top of their library until they exile a nonland card. Until end of turn, you may cast that card without paying its mana cost.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

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.

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.

Rakdos Signet

Vizier of Many Faces

You may have Vizier of Many Faces enter as a copy of any creature on the battlefield, except if Vizier of Many Faces was embalmed, the token has no mana cost, it's white, and it's a Zombie in addition to its other types.
Embalm {3}{U}{U}

Kardur, Doomscourge

When Kardur, Doomscourge enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Mindclaw Shaman

When Mindclaw Shaman enters, target opponent reveals their hand. You may cast an instant or sorcery spell from among those cards without paying its mana cost.

Nicol Bolas, God-Pharaoh

+2: Target opponent exiles cards from the top of their library until they exile a nonland card. Until end of turn, you may cast that card without paying its mana cost.
+1: Each opponent exiles two cards from their hand.
−4: Nicol Bolas, God-Pharaoh deals 7 damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.
−12: Exile each nonland permanent your opponents control.

Thraximundar

Haste
Whenever Thraximundar attacks, defending player sacrifices a creature of their choice.
Whenever a player sacrifices a creature, you may put a +1/+1 counter on Thraximundar.

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.

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}

Fallen Shinobi

Ninjutsu {2}{U}{B} ({2}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Fallen Shinobi deals combat damage to a player, that player exiles the top two cards of their library. Until end of turn, you may play those cards without paying their mana costs.

Worst Fears

You control target player during that player's next turn. Exile Worst Fears. (You see all cards that player could see and make all decisions for the player.)

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Blasphemous Act

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

Expressive Iteration

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Tibalt, Cosmic Impostor

As Tibalt enters, you get an emblem with "You may play cards exiled with Tibalt, Cosmic Impostor, and you may spend mana as though it were mana of any color to cast those spells."
+2: Exile the top card of each player's library.
−3: Exile target artifact or creature.
−8: Exile all graveyards. Add {R}{R}{R}.

Valki, God of Lies

When Valki enters, each opponent reveals their hand. For each opponent, exile a creature card they revealed this way until Valki leaves the battlefield.
{X}: Choose a creature card exiled with Valki with mana value X. Valki becomes a copy of that card.

Valki, God of Lies // Tibalt, Cosmic Impostor

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Geyadrone Dihada

Protection from permanents with corruption counters on them
+1: Each opponent loses 2 life and you gain 2 life. Put a corruption counter on up to one other target creature or planeswalker.
−3: Gain control of target creature or planeswalker until end of turn. Untap it and put a corruption counter on it. It gains haste until end of turn.
−7: Gain control of each permanent with a corruption counter on it.

Dragonlord Silumgar

Flying, deathtouch
When Dragonlord Silumgar enters, gain control of target creature or planeswalker for as long as you control Dragonlord Silumgar.

Izzet Signet

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.

Terminate

Destroy target creature. It can't be regenerated.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.