Slinking Skirge

Flying
{2}, Sacrifice Slinking Skirge: Draw a card.

Polluted Dead

When Polluted Dead dies, destroy target land.

Blood Vassal

Polluted Mire

Polluted Mire enters tapped.
{T}: Add {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Cackling Fiend

When Cackling Fiend enters, each opponent discards a card.

Spreading Rot

Destroy target land. Its controller loses 2 life.

Uncle Istvan

Prevent all damage that would be dealt to Uncle Istvan by creatures.

Despoil

Carrion Beetles

{2}{B}, {T}: Exile up to three target cards from a single graveyard.

Expunge

Destroy target nonartifact, nonblack creature. It can't be regenerated.
Cycling {2} ({2}, Discard this card: Draw a card.)

Befoul

Destroy target land or nonblack creature. It can't be regenerated.

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.

Icequake

Destroy target land. If that land was a snow land, Icequake deals 1 damage to that land's controller.

Exhume

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

Choking Sands

Destroy target non-Swamp land. If that land was nonbasic, Choking Sands deals 2 damage to the land's controller.

Sleeper's Guile

Enchant creature
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When Sleeper's Guile is put into a graveyard from the battlefield, return Sleeper's Guile to its owner's hand.

Destroy the Evidence

Destroy target land. Its controller reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Maw of the Mire

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.

Sinkhole

Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

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.)