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.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Island

Arcane Signet

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

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.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

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}

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Jace's Archivist

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

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Clever Impersonator

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

Doom Blade

Chromatic Lantern

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

Sword of Body and Mind

Equipped creature gets +2/+2 and has protection from green and from blue.
Whenever equipped creature deals combat damage to a player, you create a 2/2 green Wolf creature token and that player mills ten cards.
Equip {2}

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Mind Funeral

Target opponent reveals cards from the top of their library until four land cards are revealed. That player puts all cards revealed this way into their graveyard.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Phantasmal Image

You may have Phantasmal Image enter as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Body Double

You may have Body Double enter as a copy of any creature card in a graveyard.

Thought Collapse

Counter target spell. Its controller mills three cards.

Damnation

Destroy all creatures. They can't be regenerated.

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.

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Ashiok, Sculptor of Fears

+2: Draw a card. Each player mills two cards.
−5: Put target creature card from a graveyard onto the battlefield under your control.
−11: Gain control of all creatures target opponent controls.

Nemesis of Reason

Whenever Nemesis of Reason attacks, defending player mills ten cards.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Lazav, Dimir Mastermind

Hexproof
Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav, Dimir Mastermind become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.

Into the Story

This spell costs {3} less to cast if an opponent has seven or more cards in their graveyard.
Draw four cards.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Glimpse the Unthinkable

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Consuming Aberration

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Sky Diamond

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Sign in Blood

Target player draws two cards and loses 2 life.

Thought Vessel

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

Windfall

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

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Rhystic Study

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

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Counterspell

Cut Your Losses

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Target player mills half their library, rounded down.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Sol Ring

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Pongify

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

Lim-Dûl's Vault

Look at the top five cards of your library. As many times as you choose, you may pay 1 life, put those cards on the bottom of your library in any order, then look at the top five cards of your library. Then shuffle and put the last cards you looked at this way on top in any order.

Swamp

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Morphic Pool

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Undercover Operative

You may have Undercover Operative enter as a copy of any creature on the battlefield, except it enters with a shield counter on it if you control that creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Night's Whisper

Dimir Signet

Reanimate

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

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.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Fellwar Stone

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

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Command Tower

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Stunt Double

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