You can't win the game and your opponents can't lose the game.
6 /
6
{1}{B}{B}
Agent of the Fates
Creature - Human Assassin
Deathtouch
Heroic -- Whenever you cast a spell that targets Agent of the Fates, each opponent sacrifices a creature.
3 /
2
{4}{B}{B}
Archetype of Finality
Enchantment Creature - Gorgon
Creatures you control have deathtouch.
Creatures your opponents control lose deathtouch and can't have or gain deathtouch.
2 /
3
{3}{B}{B}
Archfiend of Depravity
Creature - Demon
Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.
5 /
4
{2}{B}
Aspect of Gorgon
Enchantment - Aura
Enchant creature
Enchanted creature gets +1/+3 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy it.)
{6}{B}{B}
Avatar of Woe
Creature - Avatar
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.
6 /
5
{2}{B}
Boon of Emrakul
Enchantment - Aura
Enchant creature
Enchanted creature gets +3/-3.
{1}{B}
Cabal Ritual
Instant
Add {B}{B}{B}.
Threshold -- Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.
{X}{B}{B}
Death Denied
Instant - Arcane
Return X target creature cards from your graveyard to your hand.
{2}{B}
Demogorgon's Clutches
Sorcery
Target opponent discards two cards, mills two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)
{3}{B}{B}
Demon of Wailing Agonies
Creature - Demon
Flying
Lieutenant -- As long as you control your commander, Demon of Wailing Agonies gets +2/+2 and has "Whenever Demon of Wailing Agonies deals combat damage to a player, that player sacrifices a creature."
4 /
4
{2}
Demon's Horn
Artifact
Whenever a player casts a black spell, you may gain 1 life.
{2}{B}{B}
Desecration Demon
Creature - Demon
Flying
At the beginning of each combat, any opponent may sacrifice a creature. If a player does, tap Desecration Demon and put a +1/+1 counter on it.
6 /
6
{2}{B}{B}
Diabolic Tutor
Sorcery
Search your library for a card, put that card into your hand, then shuffle.
{B}
Disentomb
Sorcery
Return target creature card from your graveyard to your hand.
{3}{B}{B}
Doom Whisperer
Creature - Nightmare Demon
Flying, trample
Pay 2 life: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
6 /
6
{1}{B}
Dream Devourer
Creature - Demon Cleric
Each nonland card in your hand without foretell has foretell. Its foretell cost is equal to its mana cost reduced by {2}. (During your turn, you may pay {2} and exile it from your hand face down. Cast it on a later turn for its foretell cost.)
Whenever you foretell a card, Dream Devourer gets +2/+0 until end of turn.
0 /
3
{B}
Duress
Sorcery
Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.
{7}
Elbrus, the Binding Blade
Legendary Artifact - Equipment
Equipped creature gets +1/+0.
When equipped creature deals combat damage to a player, unattach Elbrus, the Binding Blade, then transform it.
Equip {1}
--
Withengar Unbound
Legendary Creature - Demon
Flying, intimidate, trample (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a player loses the game, put thirteen +1/+1 counters on Withengar Unbound.
--
Evolving Wilds
Land
{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{B}{B}
Fear
Enchantment - Aura
Enchant creature (Target a creature as you cast this. This card enters the battlefield attached to that creature.)
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
{B}
Feign Death
Instant
Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."
{2}{B}
Grisly Transformation
Enchantment - Aura
Enchant creature
When Grisly Transformation enters the battlefield, draw a card.
Enchanted creature has intimidate. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{2}{B}
Gruesome Encore
Sorcery
Put target creature card from an opponent's graveyard onto the battlefield under your control. It gains haste. Exile it at the beginning of the next end step. If that creature would leave the battlefield, exile it instead of putting it anywhere else.
{4}{B}{B}
Harvester of Souls
Creature - Demon
Deathtouch
Whenever another nontoken creature dies, you may draw a card.
5 /
5
{5}{B}{B}
Herald of Anguish
Creature - Demon
Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Flying
At the beginning of your end step, each opponent discards a card.
{1}{B}, Sacrifice an artifact: Target creature gets -2/-2 until end of turn.
5 /
5
{1}{B}{B}
Herald of Torment
Enchantment Creature - Demon
Bestow {3}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
At the beginning of your upkeep, you lose 1 life.
Enchanted creature gets +3/+3 and has flying.
3 /
3
{1}{B}{B}
Hero's Downfall
Instant
Destroy target creature or planeswalker.
{B}{B}
Hymn to Tourach
Sorcery
Target player discards two cards at random.
{3}{B}{B}
Indulgent Tormentor
Creature - Demon
Flying
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature or pays 3 life.
5 /
3
{4}{B}{B}
Kokusho, the Evening Star
Legendary Creature - Dragon Spirit
Flying
When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.
5 /
5
{3}{B}{B}
Liliana Vess
Legendary Planeswalker - Liliana
+1: Target player discards a card.
-2: Search your library for a card, then shuffle and put that card on top.
-8: Put all creature cards from all graveyards onto the battlefield under your control.
L:
5
{2}{B}{B}
Liliana of the Dark Realms
Legendary Planeswalker - Liliana
+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
-3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.
-6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"
L:
3
{1}{B}
Macabre Waltz
Sorcery
Return up to two target creature cards from your graveyard to your hand, then discard a card.
{3}{B}
March of the Returned
Sorcery
Return up to two target creature cards from your graveyard to your hand.
{2}{B}
Mark of the Oni
Enchantment - Aura
Enchant creature
You control enchanted creature.
At the beginning of the end step, if you control no Demons, sacrifice Mark of the Oni.
{2}{B}
Mind Rot
Sorcery
Target player discards two cards.
{2}{B}{B}
Mindwrack Demon
Creature - Demon
Flying, trample
When Mindwrack Demon enters the battlefield, mill four cards.
Delirium -- At the beginning of your upkeep, you lose 4 life unless there are four or more card types among cards in your graveyard.
4 /
5
{2}{B}
Moaning Wall
Creature - Zombie Wall
Defender
Cycling {2} ({2}, Discard this card: Draw a card.)
0 /
5
{2}{B}
Necrobite
Instant
Target creature gains deathtouch until end of turn. Regenerate it. (The next time that creature would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat. Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)
{4}{B}{B}
Nefarox, Overlord of Grixis
Legendary Creature - Demon
Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever Nefarox, Overlord of Grixis attacks alone, defending player sacrifices a creature.
5 /
5
{1}{B}{B}
Nighthowler
Enchantment Creature - Horror
Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.
0 /
0
{4}{B}{B}
Ob Nixilis, Unshackled
Legendary Creature - Demon
Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.
4 /
4
{3}{B}{B}
Ob Nixilis, the Fallen
Legendary Creature - Demon
Landfall -- Whenever a land enters the battlefield under your control, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis, the Fallen.
3 /
3
{2}{B}
Phyrexian Rager
Creature - Phyrexian Horror
When Phyrexian Rager enters the battlefield, you draw a card and you lose 1 life.
2 /
2
{1}{B}
Pit Keeper
Creature - Human Wizard
When Pit Keeper enters the battlefield, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.
2 /
1
{2}{B}
Quag Sickness
Enchantment - Aura
Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.
--
Radiant Fountain
Land
When Radiant Fountain enters the battlefield, you gain 2 life.
{T}: Add {C}.
{2}{B}
Rakdos Drake
Creature - Drake
Flying
Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
1 /
2
{3}{B}{B}{B}
Reaper from the Abyss
Creature - Demon
Flying
Morbid -- At the beginning of each end step, if a creature died this turn, destroy target non-Demon creature.
6 /
6
{2}{B}
Recover
Sorcery
Return target creature card from your graveyard to your hand.
Draw a card.
{4}{B}{B}
Reign of the Pit
Sorcery
Each player sacrifices a creature. Create an X/X black Demon creature token with flying, where X is the total power of the creatures sacrificed this way.
{1}{B}
Returned Reveler
Creature - Zombie Satyr
When Returned Reveler dies, each player mills three cards.
1 /
3
{2}{B}{B}
Sangromancer
Creature - Vampire Shaman
Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.
3 /
3
{5}{B}{B}
Sheoldred, Whispering One
Legendary Creature - Phyrexian Praetor
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.
6 /
6
{B}{B}
Smallpox
Sorcery
Each player loses 1 life, discards a card, sacrifices a creature, then sacrifices a land.
{4}{B}{B}
Soul of Innistrad
Creature - Avatar
Deathtouch
{3}{B}{B}: Return up to three target creature cards from your graveyard to your hand.
{3}{B}{B}, Exile Soul of Innistrad from your graveyard: Return up to three target creature cards from your graveyard to your hand.
6 /
6
{1}{B}{B}
Soulcage Fiend
Creature - Demon
When Soulcage Fiend dies, each player loses 3 life.
3 /
2
{2}{B}
Stab Wound
Enchantment - Aura
Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.
{3}
Staff of the Death Magus
Artifact
Whenever you cast a black spell or a Swamp enters the battlefield under your control, you gain 1 life.
{B}
Strange Augmentation
Enchantment - Aura
Enchant creature
Enchanted creature gets +1/+1.
Delirium -- Enchanted creature gets an additional +2/+2 as long as there are four or more card types among cards in your graveyard.
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
{1}{B}{B}
Syphon Life
Sorcery
Target player loses 2 life and you gain 2 life.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)
{1}
Team Pennant
Artifact - Equipment
Equipped creature gets +1/+1 and has vigilance and trample.
Equip creature token {1}
Equip {3}
{3}{B}
Tendrils of Corruption
Instant
Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.
{3}{B}{B}
Tergrid, God of Fright
Legendary Creature - God
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.
4 /
5
--
Tergrid's Lantern
Legendary Artifact
{T}: Target player loses 3 life unless they sacrifice a nonland permanent or discard a card.
{3}{B}: Untap Tergrid's Lantern.
4 /
5
{3}{B}
Tree of Perdition
Creature - Plant
Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.
0 /
13
--
Tyrite Sanctum
Land
{T}: Add {C}.
{2}, {T}: Target legendary creature becomes a God in addition to its other types. Put a +1/+1 counter on it.
{4}, {T}, Sacrifice Tyrite Sanctum: Put an indestructible counter on target God.
--
Urborg, Tomb of Yawgmoth
Legendary Land
Each land is a Swamp in addition to its other land types.
{3}{B}{B}{B}
Visara the Dreadful
Legendary Creature - Gorgon
Flying
{T}: Destroy target creature. It can't be regenerated.