Bone Picker

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

Duress

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

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Cast Down

Thorn of the Black Rose

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

Barren Moor

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

Lash of Malice

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

Unmake

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.)

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.

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.

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Bojuka Bog

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

Defile

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

Echoing Decay

Target creature and all other creatures with the same name as that creature get -2/-2 until end of turn.

Wrench Mind

Target player discards two cards unless they discard an artifact card.

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.

Geth's Verdict

Target player sacrifices a creature of their choice and loses 1 life.

Phyrexian Rager

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

Swamp

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.

Chittering Rats

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

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.)

Cuombajj Witches

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

Sign in Blood

Target player draws two cards and loses 2 life.

Gurmag Angler

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