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.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Junk Diver

Flying
When Junk Diver dies, return another target artifact card from your graveyard to your hand.

Snow-Covered Swamp

Dark Ritual

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Burning-Rune Demon

Flying
When Burning-Rune Demon enters the battlefield, you may search your library for exactly two cards not named Burning-Rune Demon that have different names. If you do, reveal those cards. An opponent chooses one of them. Put the chosen card into your hand and the other into your graveyard, then shuffle.

Rune-Scarred Demon

Flying
When Rune-Scarred Demon enters the battlefield, search your library for a card, put it into your hand, then shuffle.

Persist

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

Bog Witch

Massacre Wurm

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

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: Nirkana Revenant gets +1/+1 until end of turn.

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Ashnod's Altar

Ravenous Chupacabra

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

Vile Entomber

Deathtouch
When Vile Entomber enters the battlefield, search your library for a card, put that card into your graveyard, then shuffle.

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature.

Kokusho, the Evening Star

Flying
When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Extraplanar Lens

Imprint — When Extraplanar Lens enters the battlefield, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Plaguecrafter

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

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

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.)

Sol Ring

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Dimir House Guard

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Sacrifice a creature: Regenerate Dimir House Guard.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Jet Medallion

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

Feed the Swarm

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

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Fleshbag Marauder

When Fleshbag Marauder enters the battlefield, each player sacrifices a creature.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Reanimate

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

Gauntlet of Power

As Gauntlet of Power enters the battlefield, choose a color.
Creatures of the chosen color get +1/+1.
Whenever a basic land is tapped for mana of the chosen color, its controller adds an additional one mana of that color.

Barren Moor

Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

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.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

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.

Meteor Golem

When Meteor Golem enters the battlefield, destroy target nonland permanent an opponent controls.

Swiftfoot Boots

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

Altar of Dementia

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

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Arcane Signet

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

Mind Stone

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

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Stitch Together

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Unmarked Grave

Search your library for a nonlegendary card, put that card into your graveyard, then shuffle.

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.