Snow-Covered Swamp

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.)

Night's Whisper

Rimebound Dead

{S}: Regenerate Rimebound Dead. ({S} can be paid with one mana from a snow source.)

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Sign in Blood

Target player draws two cards and loses 2 life.

Disfigure

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

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.

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.

Augur of Skulls

{1}{B}: Regenerate Augur of Skulls.
Sacrifice Augur of Skulls: Target player discards two cards. Activate only during your upkeep.

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Kjeldoran Dead

When Kjeldoran Dead enters, sacrifice a creature.
{B}: Regenerate Kjeldoran Dead.

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.

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.)

Defile

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

Death Denied

Return X target creature cards from your graveyard to your hand.

Duress

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