Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters the battlefield under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Shauku's Minion

{B}{R}, {T}: Shauku's Minion deals 2 damage to target white creature.

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature enters the battlefield under your control, if you didn't cast it from your hand, it gains haste until your next turn.

Sadistic Hypnotist

Sacrifice a creature: Target player discards two cards. Activate only as a sorcery.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Bounty Hunter

{T}: Put a bounty counter on target nonblack creature.
{T}: Destroy target creature with a bounty counter on it.

Dauthi Mindripper

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Dauthi Mindripper attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Cabal Trainee

Sacrifice Cabal Trainee: Target creature gets -2/-0 until end of turn.

Body Snatcher

When Body Snatcher enters the battlefield, exile it unless you discard a creature card.
When Body Snatcher dies, exile Body Snatcher and return target creature card from your graveyard to the battlefield.

Rag Man

{B}{B}{B}, {T}: Target opponent reveals their hand and discards a creature card at random. Activate only during your turn.

Overeager Apprentice

Discard a card, Sacrifice Overeager Apprentice: Add {B}{B}{B}.

Dauthi Marauder

Shadow (This creature can block or be blocked by only creatures with shadow.)

Dauthi Cutthroat

Shadow (This creature can block or be blocked by only creatures with shadow.)
{1}{B}, {T}: Destroy target creature with shadow.

Phyrexian Broodlings

{1}, Sacrifice a creature: Put a +1/+1 counter on Phyrexian Broodlings.

Priest of Gix

When Priest of Gix enters the battlefield, add {B}{B}{B}.

Bone Shredder

Flying
Echo {2}{B} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Bone Shredder enters the battlefield, destroy target nonartifact, nonblack creature.

Cabal Surgeon

{2}{B}{B}, {T}, Exile two cards from your graveyard: Return target creature card from your graveyard to your hand.

Cabal Torturer

{B}, {T}: Target creature gets -1/-1 until end of turn.
Threshold — {3}{B}{B}, {T}: Target creature gets -2/-2 until end of turn. Activate only if seven or more cards are in your graveyard.

Cat Burglar

{2}{B}, {T}: Target player discards a card. Activate only as a sorcery.

Cabal Inquisitor

Threshold — {1}{B}, {T}, Exile two cards from your graveyard: Target player discards a card. Activate only as a sorcery and only if seven or more cards are in your graveyard.

Chainer, Dementia Master

All Nightmares get +1/+1.
{B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types.
When Chainer, Dementia Master leaves the battlefield, exile all Nightmares.

Dirty Wererat

{B}, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can't block.

Lost Soul

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Phage the Untouchable

When Phage the Untouchable enters the battlefield, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

Sleeper Agent

When Sleeper Agent enters the battlefield, target opponent gains control of it.
At the beginning of your upkeep, Sleeper Agent deals 2 damage to you.

Treacherous Werewolf

Threshold — As long as seven or more cards are in your graveyard, Treacherous Werewolf gets +2/+2 and has "When Treacherous Werewolf dies, you lose 4 life."

Minion of the Wastes

Trample
As Minion of the Wastes enters the battlefield, pay any amount of life.
Minion of the Wastes's power and toughness are each equal to the life paid as it entered the battlefield.

Dauthi Trapper

{T}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Painbringer

{T}, Exile any number of cards from your graveyard: Target creature gets -X/-X until end of turn, where X is the number of cards exiled this way.

Gloomdrifter

Flying
Threshold — As long as seven or more cards are in your graveyard, Gloomdrifter has "When Gloomdrifter enters the battlefield, nonblack creatures get -2/-2 until end of turn."

Reclusive Wight

At the beginning of your upkeep, if you control another nonland permanent, sacrifice Reclusive Wight.

Corrupt Official

{2}{B}: Regenerate Corrupt Official.
Whenever Corrupt Official becomes blocked, defending player discards a card at random.

Duskwalker

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
If Duskwalker was kicked, it enters the battlefield with two +1/+1 counters on it and with fear. (It can't be blocked except by artifact creatures and/or black creatures.)