Memory Leak

Target opponent reveals their hand. You choose a nonland card from that player's graveyard or hand and exile it.
Cycling {1} ({1}, Discard this card: Draw a card.)

Wrench Mind

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

Exhume

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

Gurmag Angler

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

Geth's Verdict

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

Cast Down

Bojuka Bog

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

Duress

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

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Cabal Ritual

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

Icequake

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

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.)

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.

Swamp

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.

Unexpected Fangs

Put a +1/+1 counter and a lifelink counter on target creature.

Dark Ritual

Defile

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

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Drown in Sorrow

All creatures get -2/-2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)