Swamp

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.

Sign in Blood

Target player draws two cards and loses 2 life.

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.

Thorn of the Black Rose

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

Vampire Sovereign

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

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.)

Obscura Storefront

When Obscura Storefront enters the battlefield, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Crypt Rats

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

Consuming Sepulcher

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

Tithing Blade

When Tithing Blade enters the battlefield, each opponent sacrifices a creature.
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

Phyrexian Rager

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

Hopeless Nightmare

When Hopeless Nightmare enters the battlefield, 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.

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.