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.

Head Games

Target opponent puts the cards from their hand on top of their library. Search that player's library for that many cards. The player puts those cards into their hand, then shuffles.

Bond of Revival

Return target creature card from your graveyard to the battlefield. It gains haste until your next turn.

Sadistic Sacrament

Kicker {7} (You may pay an additional {7} as you cast this spell.)
Search target player's library for up to three cards, exile them, then that player shuffles. If this spell was kicked, instead search that player's library for up to fifteen cards, exile them, then that player shuffles.

Necromentia

Choose a card name other than a basic land card name. Search target opponent's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then creates a 2/2 black Zombie creature token for each card exiled from their hand this way.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• Dread Presence deals 2 damage to any target and you gain 2 life.

Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

Isolation Cell

Whenever an opponent casts a creature spell, that player loses 2 life unless they pay {2}.

Temporal Extortion

When you cast this spell, any player may pay half their life, rounded up. If a player does, counter Temporal Extortion.
Take an extra turn after this one.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, 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.)

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Life's Finale

Destroy all creatures, then search target opponent's library for up to three creature cards and put them into their graveyard. Then that player shuffles.

Trespasser's Curse

Enchant player
Whenever a creature enchanted player controls enters, that player loses 1 life and you gain 1 life.

Crypt Ghast

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.)
Whenever you tap a Swamp for mana, add an additional {B}.

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Cosmos Elixir

At the beginning of your end step, draw a card if your life total is greater than your starting life total. Otherwise, you gain 2 life.

Sol Ring

Tainted Remedy

If an opponent would gain life, that player loses that much life instead.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Dire Fleet Ravager

Menace, deathtouch
When Dire Fleet Ravager enters, each player loses a third of their life, rounded up.

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature of their choice.

Polluted Bonds

Whenever a land an opponent controls enters, that player loses 2 life and you gain 2 life.

Sower of Discord

Flying
As Sower of Discord enters, choose two players.
Whenever damage is dealt to one of the chosen players, the other chosen player also loses that much life.

Massacre Wurm

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

Ragged Veins

Flash
Enchant creature
Whenever enchanted creature is dealt damage, its controller loses that much life.

Doomed Necromancer

{B}, {T}, Sacrifice Doomed Necromancer: Return target creature card from your graveyard to the battlefield.

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.

Mind Stone

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

Nightshade Harvester

Whenever a land an opponent controls enters, that player loses 1 life. Put a +1/+1 counter on Nightshade Harvester.

Infinite Obliteration

Choose a creature card name. Search target opponent's graveyard, hand, and library for any number of cards with that name and exile them. Then that player shuffles.

Jet Medallion

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

Swamp

Dark Ritual

Avatar of Woe

If there are ten or more creature cards total in all graveyards, this spell costs {6} less to cast.
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{T}: Destroy target creature. It can't be regenerated.

Cranial Extraction

Choose a nonland card name. Search target player's graveyard, hand, and library for all cards with that name and exile them. Then that player shuffles.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Liability

Whenever a nontoken permanent is put into a player's graveyard from the battlefield, that player loses 1 life.

Entreat the Dead

Return X target creature cards from your graveyard to the battlefield.
Miracle {X}{B}{B} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Soot Imp

Flying
Whenever a player casts a nonblack spell, that player loses 1 life.

Bitter Ordeal

Search target player's library for a card and exile it. Then that player shuffles.
Gravestorm (When you cast this spell, copy it for each permanent put into a graveyard this turn. You may choose new targets for the copies.)

Memoricide

Choose a nonland card name. Search target player's graveyard, hand, and library for any number of cards with that name and exile them. Then that player shuffles.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Murder

Magus of the Coffers

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

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.

Calculating Lich

Menace
Whenever a creature attacks one of your opponents, that player loses 1 life.

Nightmare Incursion

Search target player's library for up to X cards, where X is the number of Swamps you control, and exile them. Then that player shuffles.

Jester's Cap

{2}, {T}, Sacrifice Jester's Cap: Search target player's library for three cards and exile them. Then that player shuffles.

Ancient Tomb

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

Hero's Downfall

Retreat to Hagra

Landfall — Whenever a land you control enters, choose one —
• Target creature gets +1/+0 and gains deathtouch until end of turn.
• Each opponent loses 1 life and you gain 1 life.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: Nirkana Revenant gets +1/+1 until end of turn.

Poisonbelly Ogre

Whenever another creature enters, its controller loses 1 life.

Visions of Brutality

Devoid (This card has no color.)
Enchant creature
Enchanted creature can't block.
Whenever enchanted creature deals damage, its controller loses that much life.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Mindcrank

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

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.

Charcoal Diamond

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

Consume Spirit

Spend only black mana on X.
Consume Spirit deals X damage to any target and you gain X life.

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your first main phase, add {B} for each charge counter on Black Market.

Diabolic Edict

Target player sacrifices a creature of their choice.

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Contaminated Bond

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Whenever enchanted creature attacks or blocks, its controller loses 3 life.