Crypt Rats

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

Defile

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

Trespasser's Curse

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

Gray Merchant of Asphodel

When this creature 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.)

Troll of Khazad-dûm

This creature 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.)

Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

Duress

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

Arms of Hadar

Creatures target player controls get -2/-2 until end of turn.

Sign in Blood

Target player draws two cards and loses 2 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.

Cast Down

Cuombajj Witches

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

Exhume

Each player puts a creature card from their graveyard onto the battlefield.

Swamp

Nihil Spellbomb

{T}, Sacrifice this artifact: Exile target player's graveyard.
When this artifact is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Phyrexian Rager

When this creature enters, you draw a card and you lose 1 life.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Consuming Sepulcher

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

Tithing Blade

When this artifact 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

Thorn of the Black Rose

Deathtouch
When this creature enters, you become the monarch.

Barren Moor

This land enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Chittering Rats

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