Massacre Wurm

When Massacre Wurm enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

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.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Back in Town

Return X target outlaw creature cards from your graveyard to the battlefield. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Forever Young

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Jet Medallion

Black spells you cast cost {1} less to cast.

Shriekmaw

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Shriekmaw enters, destroy target nonartifact, nonblack creature.
Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Dogged Detective

When Dogged Detective enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Whenever an opponent draws their second card each turn, you may return Dogged Detective from your graveyard to your hand.

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Go Blank

Target player discards two cards. Then exile that player's graveyard.

Altar of Dementia

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

Horobi, Death's Wail

Flying
Whenever a creature becomes the target of a spell or ability, destroy that creature.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Returned Reveler

When Returned Reveler dies, each player mills three cards.

Tombstone Stairwell

Cumulative upkeep {1}{B} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
At the beginning of each upkeep, if Tombstone Stairwell is on the battlefield, each player creates a 2/2 black Zombie creature token with haste named Tombspawn for each creature card in their graveyard.
At the beginning of each end step and when Tombstone Stairwell leaves the battlefield, destroy all tokens created with Tombstone Stairwell. They can't be regenerated.

Feed the Swarm

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

Come Back Wrong

Destroy target creature. If a creature card is put into a graveyard this way, return it to the battlefield under your control. Sacrifice it at the beginning of your next end step.

Orzhov Euthanist

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

Unseal the Necropolis

Each player mills three cards. Then you return up to two creature cards from your graveyard to your hand. (To mill three cards, a player puts the top three cards of their library into their graveyard.)

Drownyard Temple

{T}: Add {C}.
{3}: Return Drownyard Temple from your graveyard to the battlefield tapped.

Undead Butler

When Undead Butler enters, mill three cards. (Put the top three cards of your library into your graveyard.)
When Undead Butler dies, you may exile it. When you do, return target creature card from your graveyard to your hand.

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.

Whispersteel Dagger

Equipped creature gets +2/+0.
Whenever equipped creature deals combat damage to a player, you may cast a creature spell from that player's graveyard this turn, and you may spend mana as though it were mana of any color to cast that spell.
Equip {3}

Macabre Waltz

Return up to two target creature cards from your graveyard to your hand, then discard a card.

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.

Misfortune Teller

Deathtouch
Whenever Misfortune Teller enters or deals combat damage to a player, exile target card from a graveyard. If it was a creature card, create a 2/2 black Rogue creature token. If it was a land card, create a Treasure token. Otherwise, you gain 3 life.

Murder

Rush of Dread

Spree (Choose one or more additional costs.)
+ {1} — Target opponent sacrifices half the creatures they control, rounded up.
+ {2} — Target opponent discards half the cards in their hand, rounded up.
+ {2} — Target opponent loses half their life, rounded up.

Witch of the Moors

Deathtouch
At the beginning of your end step, if you gained life this turn, each opponent sacrifices a creature and you return up to one target creature card from your graveyard to your hand.

Feast of Dreams

Destroy target enchanted creature or enchantment creature.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Brood of Cockroaches

When Brood of Cockroaches is put into your graveyard from the battlefield, at the beginning of the next end step, you lose 1 life and return Brood of Cockroaches to your hand.

Doom Whisperer

Flying, trample
Pay 2 life: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Stinkweed Imp

Flying
Whenever Stinkweed Imp deals combat damage to a creature, destroy that creature.
Dredge 5 (If you would draw a card, you may mill five cards instead. If you do, return this card from your graveyard to your hand.)

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Knight of Dusk's Shadow

Menace (This creature can't be blocked except by two or more creatures.)
Your opponents can't gain life.
{1}{B}: Knight of Dusk's Shadow gets +1/+1 until end of turn.

Curtains' Call

Undaunted (This spell costs {1} less to cast for each opponent.)
Destroy two target creatures.

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Vanquish the Weak

Destroy target creature with power 3 or less.

Sinister Starfish

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Oversold Cemetery

At the beginning of your upkeep, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

Mindwrack Harpy

Flying
At the beginning of combat on your turn, each player mills three cards.

Soul Enervation

Flash
When Soul Enervation enters, target creature gets -4/-4 until end of turn.
Whenever one or more creature cards leave your graveyard, each opponent loses 1 life and you gain 1 life.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Dreadhound

When Dreadhound enters, mill three cards. (Put the top three cards of your library into your graveyard.)
Whenever a creature dies or a creature card is put into a graveyard from a library, each opponent loses 1 life.

Reassembling Skeleton

{1}{B}: Return Reassembling Skeleton from your graveyard to the battlefield tapped.

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Veinwitch Coven

Menace
Whenever you gain life, you may pay {B}. If you do, return target creature card from your graveyard to your hand.

Swamp

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

Consuming Ashes

Exile target creature. If it had mana value 3 or less, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Sol Ring

Roshan, Hidden Magister

Other creatures you control are Assassins in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
Face-down creatures you control have menace.
Whenever a permanent you control is turned face up, you draw a card and you lose 1 life.

Call for Blood

As an additional cost to cast this spell, sacrifice a creature.
Target creature gets -X/-X until end of turn, where X is the sacrificed creature's power.

Meathook Massacre II

When Meathook Massacre II enters, each player sacrifices X creatures.
Whenever a creature you control dies, you may pay 3 life. If you do, return that card under your control with a finality counter on it.
Whenever a creature an opponent controls dies, they may pay 3 life. If they don't, return that card under your control with a finality counter on it.

Macabre Reconstruction

This spell costs {2} less to cast if a creature card was put into your graveyard from anywhere this turn.
Return up to two target creature cards from your graveyard to your hand.

Sivriss, Nightmare Speaker

{T}, Sacrifice another creature or an artifact: For each opponent, you mill a card, then return that card from your graveyard to your hand unless that player pays 3 life. (To mill a card, put the top card of your library into your graveyard.)
Choose a Background (You can have a Background as a second commander.)

Necromancy

You may cast Necromancy as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
When Necromancy enters, if it's on the battlefield, it becomes an Aura with "enchant creature put onto the battlefield with Necromancy." Put target creature card from a graveyard onto the battlefield under your control and attach Necromancy to it. When Necromancy leaves the battlefield, that creature's controller sacrifices it.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Charnel Serenade

Surveil 3, then return a creature card from your graveyard to the battlefield with a finality counter on it. Exile Charnel Serenade with three time counters on it.
Suspend 3—{2}{B} (Rather than cast this card from your hand, you may pay {2}{B} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Retribution of the Ancients

{B}, Remove X +1/+1 counters from among creatures you control: Target creature gets -X/-X until end of turn.