Final-Sting Faerie

Flying
When Final-Sting Faerie enters the battlefield, destroy target creature that was dealt damage this turn.

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Attrition

{B}, Sacrifice a creature: Destroy target nonblack creature.

Fallen Ideal

Enchant creature
Enchanted creature has flying and "Sacrifice a creature: This creature gets +2/+1 until end of turn."
When Fallen Ideal is put into a graveyard from the battlefield, return Fallen Ideal to its owner's hand.

Mari, the Killing Quill

Whenever a creature an opponent controls dies, exile it with a hit counter on it.
Assassins, Mercenaries, and Rogues you control have deathtouch and "Whenever this creature deals combat damage to a player, you may remove a hit counter from a card that player owns in exile. If you do, draw a card and create two Treasure tokens."

Hellspur Posse Boss

Other outlaws you control have haste. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
When Hellspur Posse Boss enters the battlefield, create two 1/1 red Mercenary creature tokens with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Blood for the Blood God!

This spell costs {1} less to cast for each creature that died this turn.
Discard your hand, then draw eight cards. Blood for the Blood God! deals 8 damage to each opponent. Exile Blood for the Blood God!

Consecrated by Blood

Enchant creature
Enchanted creature gets +2/+2 and has flying and "Sacrifice two other creatures: Regenerate this creature." (The next time the creature would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.)

Ayara, Furnace Queen

At the beginning of combat on your turn, return up to one target artifact or creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step.

Ayara, Widow of the Realm

{T}, Sacrifice another creature or artifact: Ayara, Widow of the Realm deals X damage to target opponent or battle and you gain X life, where X is the sacrificed permanent's mana value.
{5}{R/P}: Transform Ayara. Activate only as a sorcery. ({R/P} can be paid with either {R} or 2 life.)

Ayara, Widow of the Realm // Ayara, Furnace Queen

Raffine's Silencer

When Raffine's Silencer enters the battlefield, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)
When Raffine's Silencer dies, target creature an opponent controls gets -X/-X until end of turn, where X is Raffine's Silencer's power.

Nekrataal

First strike
When Nekrataal enters the battlefield, destroy target nonartifact, nonblack creature. That creature can't be regenerated.

Fallen Angel

Flying
Sacrifice a creature: Fallen Angel gets +2/+1 until end of turn.

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Murderous Redcap

When Murderous Redcap enters the battlefield, it deals damage equal to its power to any target.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Blasting Station

{T}, Sacrifice a creature: Blasting Station deals 1 damage to any target.
Whenever a creature enters the battlefield, you may untap Blasting Station.

Caesar, Legion's Emperor

Whenever you attack, you may sacrifice another creature. When you do, choose two —
• Create two 1/1 red and white Soldier creature tokens with haste that are tapped and attacking.
• You draw a card and you lose 1 life.
• Caesar, Legion's Emperor deals damage equal to the number of creature tokens you control to target opponent.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Altar's Reap

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Backdraft Hellkite

Flying
Whenever Backdraft Hellkite attacks, each instant and sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

Martyr's Cause

Sacrifice a creature: The next time a source of your choice would deal damage to any target this turn, prevent that damage.

Stingblade Assassin

Flash
Flying
When Stingblade Assassin enters the battlefield, destroy target creature an opponent controls that was dealt damage this turn.

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Hooded Assassin

When Hooded Assassin enters the battlefield, choose one —
• Put a +1/+1 counter on Hooded Assassin.
• Destroy target creature that was dealt damage this turn.

Thermopod

{S}: Thermopod gains haste until end of turn. ({S} can be paid with one mana from a snow source.)
Sacrifice a creature: Add {R}.

At Knifepoint

As long as it's your turn, outlaws you control have first strike. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
Whenever you commit a crime, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery." This ability triggers only once each turn.

Bartolomé del Presidio

Sacrifice another creature or artifact: Put a +1/+1 counter on Bartolomé del Presidio.

Chance

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Discard any number of cards, then draw that many cards.

Leave

Return any number of target permanents you own to your hand.

Leave // Chance

Queen Marchesa

Deathtouch, haste
When Queen Marchesa enters the battlefield, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.

Aradesh, the Founder

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
Whenever a creature you control attacks, if it enlisted a creature this combat, the creature that attacked gains double strike until end of turn. If that creature's power is 4 or greater, draw a card.

Spawning Pit

Sacrifice a creature: Put a charge counter on Spawning Pit.
{1}, Remove two charge counters from Spawning Pit: Create a 2/2 colorless Spawn artifact creature token.

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters the battlefield, you become the monarch.

Olivia, Opulent Outlaw

Flying, lifelink
Whenever one or more outlaws you control deal combat damage to a player, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
{3}, Sacrifice two Treasures: Put two +1/+1 counters on each creature you control. Activate only as a sorcery.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Massacre Girl

Menace
When Massacre Girl enters the battlefield, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Altaïr Ibn-La'Ahad

First strike
Whenever Altaïr Ibn-La'Ahad attacks, exile up to one target Assassin creature card from your graveyard with a memory counter on it. Then for each creature card you own in exile with a memory counter on it, create a tapped and attacking token that's a copy of it. Exile those tokens at end of combat.

Butcher of the Horde

Flying
Sacrifice another creature: Butcher of the Horde gains your choice of vigilance, lifelink, or haste until end of turn.

Bag of Devouring

Whenever you sacrifice another nontoken artifact or creature, exile it.
{2}, {T}, Sacrifice another artifact or creature: Draw a card.
{3}, {T}, Sacrifice Bag of Devouring: Roll a d10. Return up to X cards from among cards exiled with Bag of Devouring to their owners' hands, where X is the result.

Nightshade Assassin

First strike
When Nightshade Assassin enters the battlefield, you may reveal X black cards in your hand. If you do, target creature gets -X/-X until end of turn.
Madness {1}{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.)

Ashnod's Altar

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Abolisher of Bloodlines

Flying
When this creature transforms into Abolisher of Bloodlines, target opponent sacrifices three creatures.

Voldaren Pariah

Flying
Sacrifice three other creatures: Transform Voldaren Pariah.
Madness {B}{B}{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.)

Voldaren Pariah // Abolisher of Bloodlines

Undercity Eliminator

When Undercity Eliminator enters the battlefield, you may sacrifice an artifact or creature. When you do, exile target creature an opponent controls.

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

Maw of the Obzedat

Sacrifice a creature: Creatures you control get +1/+1 until end of turn.

Big Game Hunter

When Big Game Hunter enters the battlefield, destroy target creature with power 4 or greater. It can't be regenerated.
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.)

Vraska's Finisher

When Vraska's Finisher enters the battlefield, destroy target creature or planeswalker an opponent controls that was dealt damage this turn.

Electric Revelation

As an additional cost to cast this spell, discard a card.
Draw two cards.
Flashback {3}{R} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

Goblin Assassin

Whenever Goblin Assassin or another Goblin enters the battlefield, each player flips a coin. Each player whose coin comes up tails sacrifices a creature.

Orzhov Euthanist

Haunt (When this creature dies, exile it haunting target creature.)
When Orzhov Euthanist enters the battlefield or the creature it haunts dies, destroy target creature that was dealt damage this turn.

Lurking Deadeye

Flash
When Lurking Deadeye enters the battlefield, destroy target creature that was dealt damage this turn.