Forge of Heroes

{T}: Add {C}.
{T}: Choose target commander that entered this turn. Put a +1/+1 counter on it if it's a creature and a loyalty counter on it if it's a planeswalker.

Geth, Lord of the Vault

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.

Endless Whispers

Each creature has "When this creature dies, choose target opponent. That player puts this card from its owner's graveyard onto the battlefield under their control at the beginning of the next end step."

Rat Out

Up to one target creature gets -1/-1 until end of turn. You create a 1/1 black Rat creature token with "This token can't block."

Don't Have

Howl from Beyond

Target creature gets +X/+0 until end of turn.

Phyrexian Obliterator

Trample
Whenever a source deals damage to this creature, that source's controller sacrifices that many permanents of their choice.

Herald of Torment

Bestow {3}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Flying
At the beginning of your upkeep, you lose 1 life.
Enchanted creature gets +3/+3 and has flying.

Lord of the Void

Flying
Whenever this creature deals combat damage to a player, exile the top seven cards of that player's library, then put a creature card from among them onto the battlefield under your control.

Subtle Strike

Choose one or both —
• Target creature gets -1/-1 until end of turn.
• Put a +1/+1 counter on target creature.

Sol Ring

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Netherborn Altar

{T}, Put a soul counter on this artifact: Put your commander into your hand from the command zone. Then you lose 3 life for each soul counter on this artifact.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Myriad Landscape

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

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice this artifact.

Aphotic Wisps

Target creature becomes black and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
Draw a card.

Rune-Scarred Demon

Flying
When this creature enters, search your library for a card, put it into your hand, then shuffle.

Retreat to Hagra

Landfall — Whenever a land you control enters, choose one —
• Target creature gets +1/+0 and gains deathtouch until end of turn.
• Each opponent loses 1 life and you gain 1 life.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it 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.)

Tooth of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +1/+0 until end of turn.

Horobi, Death's Wail

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

Tetzimoc, Primal Death

Deathtouch
{B}, Reveal this card from your hand: Put a prey counter on target creature. Activate only during your turn.
When Tetzimoc enters, destroy each creature your opponents control with a prey counter on it.

Ritual Chamber

When you unlock this door, create a 6/6 black Demon creature token with flying.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex

At the beginning of your end step, draw a card. If you control a Demon, each opponent loses 2 life and you gain 2 life. Otherwise, you lose 2 life.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex // Ritual Chamber

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Grim Haruspex

Morph {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.)
Whenever another nontoken creature you control dies, draw a card.

Ob Nixilis of the Black Oath

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.
−2: Create a 5/5 black Demon creature token with flying. You lose 2 life.
−8: You get an emblem with "{1}{B}, Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Leyline of the Void

If this card is in your opening hand, you may begin the game with it on the battlefield.
If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Reaper from the Abyss

Flying
Morbid — At the beginning of each end step, if a creature died this turn, destroy target non-Demon creature.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Shefet Archfiend

Flying
When this creature enters, all other creatures get -2/-2 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Darksteel Garrison

Fortified land has indestructible.
Whenever fortified land becomes tapped, target creature gets +1/+1 until end of turn.
Fortify {3} ({3}: Attach to target land you control. Fortify only as a sorcery. This card enters unattached and stays on the battlefield if the land leaves.)

Archfiend of Ifnir

Flying
Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.
Cycling {2} ({2}, Discard this card: 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.

Desert

{T}: Add {C}.
{T}: This land deals 1 damage to target attacking creature. Activate only during the end of combat step.

Unspeakable Symbol

Pay 3 life: Put a +1/+1 counter on target creature.

Unstoppable Slasher

Deathtouch
Whenever this creature deals combat damage to a player, they lose half their life, rounded up.
When this creature dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.

Fleshbag Marauder

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

Bad Moon

Massacre Wurm

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

Disfigure

Target creature gets -2/-2 until end of turn.

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis.

Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

Bloodthirsty Blade

Equipped creature gets +2/+0 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
{1}: Attach this Equipment to target creature an opponent controls. Activate only as a sorcery.

Swamp

Gisa, Glorious Resurrector

If a creature an opponent controls would die, exile it instead.
At the beginning of your upkeep, put all creature cards exiled with Gisa onto the battlefield under your control. They gain decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Mindwrack Demon

Flying, trample
When this creature enters, mill four cards.
Delirium — At the beginning of your upkeep, you lose 4 life unless there are four or more card types among cards in your graveyard.

Death Pulse

Target creature gets -4/-4 until end of turn.
Cycling {1}{B}{B} ({1}{B}{B}, Discard this card: Draw a card.)
When you cycle this card, you may have target creature get -1/-1 until end of turn.

Abyssal Harvester

{T}: Exile target creature card from a graveyard that was put there this turn. Create a token that's a copy of it, except it's a Nightmare in addition to its other types. Then exile all other Nightmare tokens you control.

Demonic Covenant

Whenever one or more Demons you control attack a player, you draw a card and lose 1 life.
At the beginning of your end step, create a 5/5 black Demon creature token with flying, then mill two cards. If two cards that share all their card types were milled this way, sacrifice this enchantment.

Desecration Demon

Flying
At the beginning of each combat, any opponent may sacrifice a creature of their choice. If a player does, tap this creature and put a +1/+1 counter on it.

Reiver Demon

Flying
When this creature enters, if you cast it from your hand, destroy all nonartifact, nonblack creatures. They can't be regenerated.

Scale of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +0/+1 until end of turn.

Doomsday Excruciator

Flying
When this creature enters, if it was cast, each player exiles all but the bottom six cards of their library face down.
At the beginning of your upkeep, draw a card.

Arcane Signet

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

Burning-Rune Demon

Flying
When this creature enters, 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.

Demonic Counsel

Search your library for a Demon card, reveal it, put it into your hand, then shuffle.
Delirium — If there are four or more card types among cards in your graveyard, instead search your library for any card, put it into your hand, then shuffle.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Drain Life

Spend only black mana on X.
Drain Life deals X damage to any target. You gain life equal to the damage dealt, but not more life than the player's life total before the damage was dealt, the planeswalker's loyalty before the damage was dealt, or the creature's toughness.

Dark Ritual

Liliana's Contract

When this enchantment enters, you draw four cards and you lose 4 life.
At the beginning of your upkeep, if you control four or more Demons with different names, you win the game.