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.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Fleshbag Marauder

When Fleshbag Marauder enters the battlefield, each player sacrifices a creature.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

The Meathook Massacre

When The Meathook Massacre enters the battlefield, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Golgari Rot Farm

Golgari Rot Farm enters the battlefield tapped.
When Golgari Rot Farm enters the battlefield, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Demon's Disciple

When Demon's Disciple enters the battlefield, each player sacrifices a creature or planeswalker.

Sol Ring

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

Ripples of Undeath

At the beginning of your precombat main phase, mill three cards. Then you may pay {1} and 3 life. If you do, put a card from among those cards into your hand.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Rushed Rebirth

Choose target creature. When that creature dies this turn, search your library for a creature card with lesser mana value, put it onto the battlefield tapped, then shuffle.

Grist, the Plague Swarm

+1: Create a 1/1 black and green Insect creature token, then mill two cards. Put a deathtouch counter on the token if a black card was milled this way.
−2: Destroy target artifact or enchantment.
−6: For each creature card in your graveyard, create a token that's a copy of it, except it's a 1/1 black and green Insect.

Grist, Voracious Larva

Deathtouch
Whenever Grist, Voracious Larva or another creature enters the battlefield under your control, if it entered from your graveyard or you cast it from your graveyard, you may pay {G}. If you do, exile Grist, then return it to the battlefield transformed under its owner's control.

Grist, Voracious Larva // Grist, the Plague Swarm

Primal Growth

Kicker—Sacrifice a creature. (You may sacrifice a creature in addition to any other costs as you cast this spell.)
Search your library for a basic land card, put that card onto the battlefield, then shuffle. If this spell was kicked, instead search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Lolth, Spider Queen

Whenever a creature you control dies, put a loyalty counter on Lolth, Spider Queen.
0: You draw a card and you lose 1 life.
−3: Create two 2/1 black Spider creature tokens with menace and reach.
−8: You get an emblem with "Whenever an opponent is dealt combat damage by one or more creatures you control, if that player lost less than 8 life this turn, they lose life equal to the difference."

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Avenger of Zendikar

When Avenger of Zendikar enters the battlefield, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land enters the battlefield under your control, you may put a +1/+1 counter on each Plant creature you control.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Haywire Mite

When Haywire Mite dies, you gain 2 life.
{G}, Sacrifice Haywire Mite: Exile target noncreature artifact or noncreature enchantment.

Plaguecrafter

When Plaguecrafter enters the battlefield, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Deadly Rollick

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

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

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.)

Eldritch Evolution

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card with mana value X or less, where X is 2 plus the sacrificed creature's mana value. Put that card onto the battlefield, then shuffle. Exile Eldritch Evolution.

Malakir Mire

Malakir Mire enters the battlefield tapped.
{T}: Add {B}.

Malakir Rebirth

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Rebirth // Malakir Mire

Solemn Simulacrum

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

Massacre Wurm

When Massacre Wurm enters the battlefield, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Khalni Garden

Khalni Garden enters the battlefield tapped.
When Khalni Garden enters the battlefield, create a 0/1 green Plant creature token.
{T}: Add {G}.

Arcane Signet

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

Nine-Lives Familiar

This creature enters with eight revival counters on it if you cast it.
When this creature dies, if it had a revival counter on it, return it to the battlefield with one fewer revival counter on it at the beginning of the next end step.

Atzal, Cave of Eternity

(Transforms from Journey to Eternity.)
{T}: Add one mana of any color.
{3}{B}{G}, {T}: Return target creature card from your graveyard to the battlefield.

Journey to Eternity

Enchant creature you control
When enchanted creature dies, return it to the battlefield under your control, then return Journey to Eternity to the battlefield transformed under your control.

Journey to Eternity // Atzal, Cave of Eternity

Accursed Marauder

When Accursed Marauder enters the battlefield, each player sacrifices a nontoken creature.

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Blooming Marsh

Blooming Marsh enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {B} or {G}.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Rise of the Dark Realms

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

Skullclamp

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

Swamp

Command Tower

Orcish Bowmasters

Flash
When Orcish Bowmasters enters the battlefield and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Undergrowth Stadium

Undergrowth Stadium enters the battlefield tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Protean Hulk

When Protean Hulk dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

Forest

Warren Soultrader

Pay 1 life, Sacrifice another creature: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Infernal Grasp

Destroy target creature. You lose 2 life.

Saw in Half

Destroy target creature. If that creature dies this way, its controller creates two tokens that are copies of that creature, except their base power is half that creature's power and their base toughness is half that creature's toughness. Round up each time.

Woodland Cemetery

Woodland Cemetery enters the battlefield tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Deathcap Glade

Deathcap Glade enters the battlefield tapped unless you control two or more other lands.
{T}: Add {B} or {G}.

Izoni, Thousand-Eyed

Undergrowth — When Izoni, Thousand-Eyed enters the battlefield, create a 1/1 black and green Insect creature token for each creature card in your graveyard.
{B}{G}, Sacrifice another creature: You gain 1 life and draw a card.

Flare of Cultivation

You may sacrifice a nontoken green creature rather than pay this spell's mana cost.
Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Foundation Breaker

When Foundation Breaker enters the battlefield, you may destroy target artifact or enchantment.
Evoke {1}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

Tergrid, God of Fright // Tergrid's Lantern

Drivnod, Carnage Dominus

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{B/P}{B/P}, Exile three creature cards from your graveyard: Put an indestructible counter on Drivnod, Carnage Dominus. ({B/P} can be paid with either {B} or 2 life.)

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Woe Strider

When Woe Strider enters the battlefield, create a 0/1 white Goat creature token.
Sacrifice another creature: Scry 1.
Escape—{3}{B}{B}, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Woe Strider escapes with two +1/+1 counters on it.

Underground Mortuary

({T}: Add {B} or {G}.)
Underground Mortuary enters the battlefield tapped.
When Underground Mortuary enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Cankerbloom

{1}, Sacrifice Cankerbloom: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Compy Swarm

At the beginning of your end step, if a creature died this turn, create a tapped token that's a copy of Compy Swarm.

High Market

{T}: Add {C}.
{T}, Sacrifice a creature: You gain 1 life.

Moldervine Reclamation

Whenever a creature you control dies, you gain 1 life and draw a card.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Necroblossom Snarl

As Necroblossom Snarl enters the battlefield, you may reveal a Swamp or Forest card from your hand. If you don't, Necroblossom Snarl enters the battlefield tapped.
{T}: Add {B} or {G}.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Soul Shatter

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

Twilight Mire

{T}: Add {C}.
{B/G}, {T}: Add {B}{B}, {B}{G}, or {G}{G}.

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.")

Wood Elves

When Wood Elves enters the battlefield, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Butcher of Malakir

Flying
Whenever Butcher of Malakir or another creature you control dies, each opponent sacrifices a creature.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Shriekmaw

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Shriekmaw enters the battlefield, destroy target nonartifact, nonblack creature.
Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Reanimate

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

Merciless Executioner

When Merciless Executioner enters the battlefield, each player sacrifices a creature.