Bojuka Bog

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

Diabolic Edict

Target player sacrifices a creature of their choice.

Cuombajj Witches

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

Have

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.)

Phyrexian Rager

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

Cast Down

Swamp

Sign in Blood

Target player draws two cards and loses 2 life.

Disfigure

Target creature gets -2/-2 until end of turn.

Chittering Rats

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

Gurmag Angler

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

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters, you become the monarch.

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.

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.