Bone Shards

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

Swamp

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.)

Foul Imp

Flying
When Foul Imp enters, you lose 2 life.

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.)

Banehound

Pit Keeper

When Pit Keeper enters, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

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.

Mesmeric Fiend

When Mesmeric Fiend enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When Mesmeric Fiend leaves the battlefield, return the exiled card to its owner's hand.

Bile Urchin

Sacrifice Bile Urchin: Target player loses 1 life.

Sedgemoor Witch

Menace
Ward—Pay 3 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 3 life.)
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."

Reave Soul

Destroy target creature with power 3 or less.

Cultist's Staff

Equipped creature gets +2/+2.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Horrifying Revelation

Target player discards a card, then mills a card.

Onyx Mage

{1}{B}: Target creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Cauldron Familiar

When Cauldron Familiar enters, each opponent loses 1 life and you gain 1 life.
Sacrifice a Food: Return Cauldron Familiar from your graveyard to the battlefield.

Plague Witch

{B}, {T}, Discard a card: Target creature gets -1/-1 until end of turn.

Death Cultist

Sacrifice Death Cultist: Target player loses 1 life and you gain 1 life.

Augur of Skulls

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

Feed the Swarm

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

Yoke of the Damned

Enchant creature
When a creature dies, destroy enchanted creature.

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.)