Defile

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

Choking Sands

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

Oblivion Crown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature has "Discard a card: This creature gets +1/+1 until end of turn."

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.

Snow-Covered Swamp

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.)

Headless Specter

Flying
Hellbent — Whenever this creature deals combat damage to a player, if you have no cards in hand, that player discards a card at random.

Last Rites

Discard any number of cards. Target player reveals their hand, then you choose a nonland card from it for each card discarded this way. That player discards those cards.

Lotus Petal

{T}, Sacrifice this artifact: Add one mana of any color.

Bojuka Bog

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

Swamp

Icequake

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

Vampire Sovereign

Flying
When this creature enters, target opponent loses 3 life and you gain 3 life.

Sign in Blood

Target player draws two cards and loses 2 life.

Witch's Cottage

({T}: Add {B}.)
This land enters tapped unless you control three or more other Swamps.
When this land enters untapped, you may put target creature card from your graveyard on top of your library.

Demon's Jester

Flying
Hellbent — This creature gets +2/+1 as long as you have no cards in hand.

Alms of the Vein

Target opponent loses 3 life and you gain 3 life.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Cutthroat il-Dal

Hellbent — This creature has shadow as long as you have no cards in hand. (It can block or be blocked by only creatures with shadow.)

Dark Ritual

Duress

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