Bhaal, Lord of Murder

As long as your life total is less than or equal to half your starting life total, Bhaal, Lord of Murder has indestructible.
Whenever another nontoken creature you control dies, put a +1/+1 counter on target creature and goad it.

Slaughter Specialist

When Slaughter Specialist enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Slaughter Specialist.

Sphere of Annihilation

Sphere of Annihilation enters with X void counters on it.
At the beginning of your upkeep, exile Sphere of Annihilation, all creatures and planeswalkers with mana value less than or equal to the number of void counters on it, and all creature and planeswalker cards in graveyards with mana value less than or equal to the number of void counters on it.

Kill! Maim! Burn!

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Kill! Maim! Burn! deals 3 damage to target player.

Execute

Destroy target white creature. It can't be regenerated.
Draw a card.

Massacre Girl

Menace
When Massacre Girl enters, 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.

Undead Executioner

When Undead Executioner dies, you may have target creature get -2/-2 until end of turn.

Slaughter Pact

Destroy target nonblack creature.
At the beginning of your next upkeep, pay {2}{B}. If you don't, you lose the game.

Annihilate

Destroy target nonblack creature. It can't be regenerated.
Draw a card.

Falkenrath Exterminator

Whenever Falkenrath Exterminator deals combat damage to a player, put a +1/+1 counter on it.
{2}{R}: Falkenrath Exterminator deals damage to target creature equal to the number of +1/+1 counters on Falkenrath Exterminator.

Slaughter

Buyback—Pay 4 life. (You may pay 4 life in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Destroy target nonblack creature. It can't be regenerated.

Annihilating Glare

As an additional cost to cast this spell, pay {4} or sacrifice an artifact or creature.
Destroy target creature or planeswalker.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Gimli, Counter of Kills

Trample
Whenever a creature an opponent controls dies, Gimli, Counter of Kills deals 1 damage to that creature's controller.

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. Karplusan Forest deals 1 damage to you.

Slaughter-Priest of Mogis

Whenever you sacrifice a permanent, Slaughter-Priest of Mogis gets +2/+0 until end of turn.
{2}, Sacrifice another creature or an enchantment: Slaughter-Priest of Mogis gains first strike until end of turn.

Annihilating Fire

Annihilating Fire deals 3 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.

The Bloodsky Massacre

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 2/3 red Demon Berserker creature token with menace.
II — Whenever a Berserker attacks this turn, you draw a card and you lose 1 life.
III — Add {R} for each Berserker you control. Until end of turn, you don't lose this mana as steps and phases end.

Ashling, the Extinguisher

Whenever Ashling, the Extinguisher deals combat damage to a player, choose target creature that player controls. The player sacrifices that creature.

Tymaret, the Murder King

{1}{R}, Sacrifice another creature: Tymaret, the Murder King deals 2 damage to target player or planeswalker.
{1}{B}, Sacrifice a creature: Return Tymaret from your graveyard to your hand.

Murderous Compulsion

Destroy target tapped creature.
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.)

Thrill-Kill Assassin

Deathtouch
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Exterminate!

Replicate—Tap an untapped Dalek you control. (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Destroy target creature. Its controller loses 3 life.

Executioner's Capsule

{1}{B}, {T}, Sacrifice Executioner's Capsule: Destroy target nonblack creature.

Murder

Slaughter Cry

Target creature gets +3/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Eliminate

Destroy target creature or planeswalker with mana value 3 or less.

Executioner's Hood

Equipped creature has intimidate. (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Rustrazor Butcher

First strike
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Skulking Killer

When Skulking Killer enters, target creature an opponent controls gets -2/-2 until end of turn if that opponent controls no other creatures.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

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."

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Viashino Slaughtermaster

Double strike
{B}{G}: Viashino Slaughtermaster gets +1/+1 until end of turn. Activate only once each turn.

Slaughterhorn

Bloodrush — {G}, Discard Slaughterhorn: Target attacking creature gets +3/+2 until end of turn.

Risen Executioner

Risen Executioner can't block.
Other Zombie creatures you control get +1/+1.
You may cast Risen Executioner from your graveyard if you pay {1} more to cast it for each other creature card in your graveyard.

Gruul Turf

Gruul Turf enters tapped.
When Gruul Turf enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Mountain

Mogis, God of Slaughter

Indestructible
As long as your devotion to black and red is less than seven, Mogis isn't a creature.
At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature of their choice.

To the Slaughter

Target player sacrifices a creature or planeswalker of their choice.
Delirium — If there are four or more card types among cards in your graveyard, instead that player sacrifices a creature and a planeswalker of their choice.

Kozilek, Butcher of Truth

When you cast this spell, draw four cards.
Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents of their choice.)
When Kozilek, Butcher of Truth is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Massacre

If an opponent controls a Plains and you control a Swamp, you may cast this spell without paying its mana cost.
All creatures get -2/-2 until end of turn.

Massacre Girl, Known Killer

Menace
Creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls dies, if its toughness was less than 1, draw a card.

Woodland Cemetery

Woodland Cemetery enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Killer Instinct

At the beginning of your upkeep, reveal the top card of your library. If it's a creature card, put it onto the battlefield. That creature gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Assassinate

Undercity Eliminator

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

Eliminate the Competition

As an additional cost to cast this spell, sacrifice X creatures.
Destroy X target creatures.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Killer Bees

Flying
{G}: Killer Bees gets +1/+1 until end of turn.

Aphetto Exterminator

Morph {3}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Aphetto Exterminator is turned face up, target creature gets -3/-3 until end of turn.

Swamp

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Terminate

Destroy target creature. It can't be regenerated.

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature of their choice.

Kill-Zone Acrobat

Whenever Kill-Zone Acrobat attacks, you may sacrifice another creature or artifact. If you do, Kill-Zone Acrobat gains flying until end of turn.

Murderer's Axe

Equipped creature gets +2/+2.
Equip—Discard a card.

Chaos Terminator Lord

Lord of Chaos — At the beginning of combat on your turn, another target creature you control gains double strike until end of turn.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Public Execution

Destroy target creature an opponent controls. Each other creature that player controls gets -2/-0 until end of turn.

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Thrill-Kill Disciple

Squad—{1}, Discard a card. (As an additional cost to cast this spell, you may pay its squad cost any number of times. When this creature enters, create that many tokens that are copies of it.)
When Thrill-Kill Disciple dies, create a Junk token.

Vraan, Executioner Thane

Whenever one or more other creatures you control die, each opponent loses 2 life and you gain 2 life. This ability triggers only once each turn.

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Forest

Killing Glare

Destroy target creature with power X or less.

Ziatora's Proving Ground

({T}: Add {B}, {R}, or {G}.)
Ziatora's Proving Ground enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Contract Killing

Destroy target creature. Create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Kill-Suit Cultist

Kill-Suit Cultist attacks each combat if able.
{B}, Sacrifice Kill-Suit Cultist: The next time damage would be dealt to target creature this turn, destroy that creature instead.

Murderous Cut

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Destroy target creature.

Slaughter Games

This spell can't be countered.
Choose a nonland card name. Search target opponent's graveyard, hand, and library for any number of cards with that name and exile them. Then that player shuffles.

A Killer Among Us

When A Killer Among Us enters, create a 1/1 white Human creature token, a 1/1 blue Merfolk creature token, and a 1/1 red Goblin creature token. Then secretly choose Human, Merfolk, or Goblin.
Sacrifice A Killer Among Us, Reveal the creature type you chose: If target attacking creature token is the chosen type, put three +1/+1 counters on it and it gains deathtouch until end of turn.

Termination Facilitator

{T}: Put a bounty counter on target creature or planeswalker. Activate only as a sorcery.
Whenever a creature or planeswalker an opponent controls with a bounty counter on it is dealt damage, destroy it.

Wake to Slaughter

Choose up to two target creature cards in your graveyard. An opponent chooses one of them. Return that card to your hand. Return the other to the battlefield under your control. It gains haste. Exile it at the beginning of the next end step.
Flashback {4}{B}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Chandra, Dressed to Kill

+1: Add {R}. Chandra, Dressed to Kill deals 1 damage to up to one target player or planeswalker.
+1: Exile the top card of your library. If it's red, you may cast it this turn.
−7: Exile the top five cards of your library. You may cast red spells from among them this turn. You get an emblem with "Whenever you cast a red spell, this emblem deals X damage to any target, where X is the amount of mana spent to cast that spell."

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.