Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
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.)

Bone Picker

This spell costs {3} less to cast if a creature died this turn.
Flying, deathtouch

Drown in Sorrow

All creatures get -2/-2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Cuombajj Witches

{T}: Cuombajj Witches deals 1 damage to any target and 1 damage to any target of an opponent's choice.

Dauthi Slayer

Shadow (This creature can block or be blocked by only creatures with shadow.)
Dauthi Slayer attacks each combat if able.

Contaminated Ground

Enchant land
Enchanted land is a Swamp.
Whenever enchanted land becomes tapped, its controller loses 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.)

Vampire Sovereign

Flying
When Vampire Sovereign enters, target opponent loses 3 life and you gain 3 life.

Vault of Whispers

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.)

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Sign in Blood

Target player draws two cards and loses 2 life.

Carrion Feeder

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

Consuming Sepulcher

At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Tithing Blade

When Tithing Blade enters, each opponent sacrifices a creature of their choice.
Craft with creature {4}{B} ({4}{B}, Exile this artifact, Exile a creature you control or a creature card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Tithing Blade // Consuming Sepulcher

Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Stinkweed Imp

Flying
Whenever Stinkweed Imp deals combat damage to a creature, destroy that creature.
Dredge 5 (If you would draw a card, you may mill five cards instead. If you do, return this card from your graveyard to your hand.)

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Rowan's Grim Search

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
If this spell was bargained, look at the top four cards of your library, then put up to two of them back on top of your library in any order and the rest into your graveyard.
You draw two cards and you lose 2 life.

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Sanitarium Skeleton

{2}{B}: Return Sanitarium Skeleton from your graveyard to your hand.

Crypt Rats

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

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Phyrexian Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

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.

Swamp

Witch's Cottage

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

Oubliette

When Oubliette enters, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Dusk Legion Zealot

When Dusk Legion Zealot enters, you draw a card and you lose 1 life.

Blood Fountain

When Blood Fountain enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{3}{B}, {T}, Sacrifice Blood Fountain: Return up to two target creature cards from your graveyard to your hand.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Hopeless Nightmare

When Hopeless Nightmare enters, each opponent discards a card and loses 2 life.
When Hopeless Nightmare is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice Hopeless Nightmare.

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Mephitic Draught

When Mephitic Draught enters or is put into a graveyard from the battlefield, you draw a card and you lose 1 life.

Chittering Rats

When Chittering Rats enters, target opponent puts a card from their hand on top of their library.