Ob Nixilis's Cruelty

Target creature gets -5/-5 until end of turn. If that creature would die this turn, exile it instead.

Culling Drone

Devoid (This card has no color.)
Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Underworld Charger

Underworld Charger can't block.
Escape—{4}{B}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
Underworld Charger escapes with two +1/+1 counters on it.

Locthwain Paladin

Menace (This creature can't be blocked except by two or more creatures.)
Adamant — If at least three black mana was spent to cast this spell, Locthwain Paladin enters with a +1/+1 counter on it.

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

Eternal Taskmaster

Eternal Taskmaster enters tapped.
Whenever Eternal Taskmaster attacks, you may pay {2}{B}. If you do, return target creature card from your graveyard to your hand.

Spark Harvest

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Destroy target creature or planeswalker.

Heartless Act

Choose one —
• Destroy target creature with no counters on it.
• Remove up to three counters from target creature.

Diregraf Ghoul

Blood for Bones

As an additional cost to cast this spell, sacrifice a creature.
Return a creature card from your graveyard to the battlefield, then return another creature card from your graveyard to your hand.

Return from Extinction

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target creature cards that share a creature type from your graveyard to your hand.

Drag to the Underworld

This spell costs {X} less to cast, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Destroy target creature.

Foreboding Fruit

Target player draws two cards and loses 2 life.
Adamant — If at least three black mana was spent to cast this spell, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Dark Bargain

Look at the top three cards of your library. Put two of them into your hand and the other into your graveyard. Dark Bargain deals 2 damage to you.

Nightsquad Commando

When Nightsquad Commando enters, if you attacked this turn, create a 1/1 white Human Soldier creature token.