Demon of Wailing Agonies

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."

Shadows of the Past

Whenever a creature dies, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)
{4}{B}: Each opponent loses 2 life and you gain 2 life. Activate only if there are four or more creature cards in your graveyard.

Swamp

Consuming Vapors

Target player sacrifices a creature. You gain life equal to that creature's toughness.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Skull Collector

At the beginning of your upkeep, return a black creature you control to its owner's hand.
{1}{B}: Regenerate Skull Collector.

Harvester of Souls

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

Gravedigger

When Gravedigger enters the battlefield, you may return target creature card from your graveyard to your hand.

Corpse Augur

When Corpse Augur dies, you draw X cards and you lose X life, where X is the number of creature cards in target player's graveyard.

Polluted Mire

Polluted Mire enters the battlefield tapped.
{T}: Add {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Barter in Blood

Stronghold Assassin

{T}, Sacrifice a creature: Destroy target nonblack creature.

Magus of the Abyss

At the beginning of each player's upkeep, destroy target nonartifact creature that player controls of their choice. It can't be regenerated.

Dark Ritual

Zombify

Return target creature card from your graveyard to the battlefield.

Fleshbag Marauder

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

Phyrexian Tribute

As an additional cost to cast this spell, sacrifice two creatures.
Destroy target artifact.

Lim-Dûl the Necromancer

Whenever a creature an opponent controls dies, you may pay {1}{B}. If you do, return that card to the battlefield under your control. If it's a creature, it's a Zombie in addition to its other creature types.
{1}{B}: Regenerate target Zombie.

Dingus Staff

Whenever a creature dies, Dingus Staff deals 2 damage to that creature's controller.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Zulaport Cutthroat

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

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Mindwrack 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.

Royal Assassin

Bone Shredder

Flying
Echo {2}{B} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Bone Shredder enters the battlefield, destroy target nonartifact, nonblack creature.

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.)

Umbra Stalker

Chroma — Umbra Stalker's power and toughness are each equal to the number of black mana symbols in the mana costs of cards in your graveyard.

Sudden Death

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Target creature gets -4/-4 until end of turn.

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Eye Collector

Flying
Whenever Eye Collector deals combat damage to a player, each player mills a card.

Apprentice Necromancer

{B}, {T}, Sacrifice Apprentice Necromancer: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.

Ur-Golem's Eye

Revenant

Flying
Revenant's power and toughness are each equal to the number of creature cards in your graveyard.

Reassembling Skeleton

{1}{B}: Return Reassembling Skeleton from your graveyard to the battlefield tapped.

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters the battlefield tapped unless you control three or more other Swamps.
When Witch's Cottage enters the battlefield untapped, you may put target creature card from your graveyard on top of your library.

Spike Cannibal

Spike Cannibal enters the battlefield with a +1/+1 counter on it.
When Spike Cannibal enters the battlefield, move all +1/+1 counters from all creatures onto it.

Black Market

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

Vampire Nighthawk

Merciless Executioner

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

Ashen Ghoul

Haste
{B}: Return Ashen Ghoul from your graveyard to the battlefield. Activate only during your upkeep and only if three or more creature cards are above Ashen Ghoul.

Revel in Riches

Whenever a creature an opponent controls dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.

Fallen Angel

Flying
Sacrifice a creature: Fallen Angel gets +2/+1 until end of turn.

Bonehoard

Living weapon (When this Equipment enters the battlefield, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +X/+X, where X is the number of creature cards in all graveyards.
Equip {2}

Sign in Blood

Target player draws two cards and loses 2 life.

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

Murder

Barren Moor

Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Diabolic Tutor

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

Fleshwrither

Transfigure {1}{B}{B} ({1}{B}{B}, Sacrifice this creature: Search your library for a creature card with the same mana value as this creature, put that card onto the battlefield, then shuffle. Transfigure only as a sorcery.)

Witch's Vengeance

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

Victimize

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

Spoils of Blood

Create an X/X black Horror creature token, where X is the number of creatures that died this turn.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Spinning Darkness

You may exile the top three black cards of your graveyard rather than pay this spell's mana cost.
Spinning Darkness deals 3 damage to target nonblack creature. You gain 3 life.

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature, then sacrifices a land.

Morality Shift

Exchange your graveyard and library. Then shuffle your library.

Leaden Myr

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.)

Gorging Vulture

Flying
When Gorging Vulture enters the battlefield, mill four cards. You gain 1 life for each creature card milled this way. (To mill four cards, put the top four cards of your library into your graveyard.)

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Geth, Lord of the Vault

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.

Mindcrank

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

Indulgent Tormentor

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

Bloodgift Demon

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

Hired Poisoner

Nekrataal

First strike
When Nekrataal enters the battlefield, destroy target nonartifact, nonblack creature. That creature can't be regenerated.

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.