Geothermal Bog

({T}: Add {B} or {R}.)
Geothermal Bog enters tapped.

Swirling Sandstorm

Threshold — Swirling Sandstorm deals 5 damage to each creature without flying if seven or more cards are in your graveyard.

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Pulling Teeth

Clash with an opponent. If you win, target player discards two cards. Otherwise, that player discards a card. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Cast Down

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Barren Moor

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

Swamp

Campfire

{1}, {T}: You gain 2 life.
{2}, {T}, Exile Campfire: Put all commanders you own from the command zone and from your graveyard into your hand. Then shuffle your graveyard into your library.

Fruit of Tizerus

Target player loses 2 life.
Escape—{3}{B}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Bojuka Bog

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

Unscrupulous Agent

When Unscrupulous Agent enters, target opponent exiles a card from their hand.

Mountain

Skullcap Snail

When Skullcap Snail enters, target opponent exiles a card from their hand.

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.

Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Hopeless Nightmare

When Hopeless Nightmare enters, 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.