Hell Mongrel

Discard a card: Hell Mongrel gets +1/+1 until end of turn.
Madness {2}{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.)

Sign in Blood

Target player draws two cards and loses 2 life.

Cabal Initiate

Discard a card: Cabal Initiate gains lifelink until end of turn.
Threshold — Cabal Initiate gets +1/+2 as long as seven or more cards are in your graveyard.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Crypt Lurker

When Crypt Lurker enters, you may sacrifice a creature or discard a creature card. If you do, draw a card.

Swamp

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

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.)

Soulcage Fiend

When Soulcage Fiend dies, each player loses 3 life.

Etched Familiar

When Etched Familiar dies, each opponent loses 2 life and you gain 2 life.

Gathan Raiders

Hellbent — Gathan Raiders gets +2/+2 as long as you have no cards in hand.
Morph—Discard a card. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Wild Mongrel

Discard a card: Wild Mongrel gets +1/+1 and becomes the color of your choice until end of turn.

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.)

Dark Withering

Destroy target nonblack creature.
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.)

Vampire Spawn

When this creature enters, each opponent loses 2 life and you gain 2 life.

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.)

Deep Goblin Skulltaker

Menace
At the beginning of your end step, if you descended this turn, put a +1/+1 counter on Deep Goblin Skulltaker. (You descended if a permanent card was put into your graveyard from anywhere.)

Odious Witch

Whenever Odious Witch attacks, defending player loses 1 life and you gain 1 life.

Ragged Recluse

At the beginning of your end step, if you discarded a card this turn, transform Ragged Recluse.

Ragged Recluse // Odious Witch

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.)

Call to the Netherworld

Return target black creature card from your graveyard to your hand.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Grisly Survivor

Whenever you cycle or discard a card, Grisly Survivor gets +2/+0 until end of turn.

Vampire's Kiss

Target player loses 2 life and you gain 2 life. Create two Blood tokens. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Kitchen Imp

Flying, haste
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.)

Kozilek's Shrieker

Devoid (This card has no color.)
{C}: Kozilek's Shrieker gets +1/+0 and gains menace until end of turn. (It can't be blocked except by two or more creatures. {C} represents colorless mana.)

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.