Cabal Coffers

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

Abyssal Persecutor

Flying, trample
You can't win the game and your opponents can't lose the game.

Dark Ritual

Witch's Vengeance

Creatures of the creature type of your choice get -3/-3 until end of turn.

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Doom Whisperer

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.)

Soulcage Fiend

When Soulcage Fiend dies, each player loses 3 life.

Reaper from the Abyss

Flying
Morbid — At the beginning of each end step, if a creature died this turn, destroy target non-Demon creature.

Herald of Anguish

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.

Indulgent Tormentor

Flying
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature or pays 3 life.

Torment of Hailfire

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

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Nefarox, Overlord of Grixis

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.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Return to Action

Until end of turn, target creature gets +1/+0 and gains lifelink and "When this creature dies, return it to the battlefield tapped under its owner's control."

Master of the Feast

Flying
At the beginning of your upkeep, each opponent draws a card.

Herald of Torment

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.

Taborax, Hope's Demise

Flying
Taborax, Hope's Demise has lifelink as long as it has five or more +1/+1 counters on it.
Whenever another nontoken creature you control dies, put a +1/+1 counter on Taborax. If that creature was a Cleric, you may draw a card. If you do, you lose 1 life.

Plague Drone

Flying
Rot Fly — If an opponent would gain life, that player loses that much life instead.

Demon of Death's Gate

You may pay 6 life and sacrifice three black creatures rather than pay this spell's mana cost.
Flying, trample

Swamp

Desecration 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.

Sign in Blood

Target player draws two cards and loses 2 life.

Profane Tutor

Suspend 2—{1}{B} (Rather than cast this card from your hand, pay {1}{B} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search your library for a card, put that card into your hand, then shuffle.

Toxrill, the Corrosive

At the beginning of each end step, put a slime counter on each creature you don't control.
Creatures you don't control get -1/-1 for each slime counter on them.
Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token.
{U}{B}, Sacrifice a Slug: Draw a card.

Disentomb

Return target creature card from your graveyard to your hand.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Bloodgift Demon

Flying
At the beginning of your upkeep, target player draws a card and loses 1 life.

Heartless Summoning

Creature spells you cast cost {2} less to cast.
Creatures you control get -1/-1.

Harvester of Souls

Deathtouch
Whenever another nontoken creature dies, you may draw a card.

Murder

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

Phyrexian Arena

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

Nightmare Shepherd

Flying
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and it's a Nightmare in addition to its other types.

Ob Nixilis Reignited

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

Reiver Demon

Flying
When Reiver Demon enters, if you cast it from your hand, destroy all nonartifact, nonblack creatures. They can't be regenerated.

Grimoire of the Dead

{1}, {T}, Discard a card: Put a study counter on Grimoire of the Dead.
{T}, Remove three study counters from Grimoire of the Dead and sacrifice it: Put all creature cards from all graveyards onto the battlefield under your control. They're black Zombies in addition to their other colors and types.

Extractor Demon

Flying
Whenever another creature leaves the battlefield, you may have target player mill two cards.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Ob Nixilis, the Fallen

Landfall — Whenever a land you control enters, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis, the Fallen.

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.

Ob Nixilis, Unshackled

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.

Phyrexian Obliterator

Trample
Whenever a source deals damage to Phyrexian Obliterator, that source's controller sacrifices that many permanents.

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Blood Tithe

Each opponent loses 3 life. You gain life equal to the life lost this way.

Exsanguinate

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

Ob Nixilis of the Black Oath

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.
−2: Create a 5/5 black Demon creature token with flying. You lose 2 life.
−8: You get an emblem with "{1}{B}, Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

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.