Pure discard

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.

Bojuka Bog

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

Removal

Chainer's Edict

Target player sacrifices a creature.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Other

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.)

Rowan's Grim Search

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
If this spell was bargained, look at the top four cards of your library, then put up to two of them back on top of your library in any order and the rest into your graveyard.
You draw two cards and you lose 2 life.

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Trespasser's Curse

Enchant player
Whenever a creature enchanted player controls enters, that player loses 1 life and you gain 1 life.

Wight of Precinct Six

Wight of Precinct Six gets +1/+1 for each creature card in your opponents' graveyards.

wincons

Syphon Life

Target player loses 2 life and you gain 2 life.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Cast Down

Raven's Crime

Target player discards a card.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Gurmag Angler

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

Chittering Rats

When Chittering Rats enters, target opponent puts a card from their hand on top of their library.

Wrench Mind

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

Defile

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

Duress

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

Innocent Blood

Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

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.)

Swamp

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Funeral Charm

Choose one —
• Target player discards a card.
• Target creature gets +2/-1 until end of turn.
• Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Crypt Rats

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

Tasigur's Cruelty

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