Rune-Scarred Demon

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

Rafter Demon

Spectacle {3}{B}{R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
When this creature enters, if its spectacle cost was paid, each opponent discards a card.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Song-Mad Ruins

Song-Mad Treachery

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Song-Mad Treachery // Song-Mad Ruins

Necropolis Fiend

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying
{X}, {T}, Exile X cards from your graveyard: Target creature gets -X/-X until end of turn.

Hijack

Gain control of target artifact or creature until end of turn. Untap it. It gains haste until end of turn.

Temporary Insanity

Untap target creature with power less than the number of cards in your graveyard and gain control of it until end of turn. That creature gains haste until end of turn.

Thraxodemon

{3}, {T}, Sacrifice another creature or artifact: Draw a card.

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

Mindsplice Apparatus

Flash
At the beginning of your upkeep, put an oil counter on this artifact.
Instant and sorcery spells you cast cost {1} less to cast for each oil counter on this artifact.

Death-Rattle Oni

Flash
This spell costs {2} less to cast for each creature that died this turn.
When this creature enters, destroy all other creatures that were dealt damage this turn.

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Silent-Blade Oni

Ninjutsu {4}{U}{B} ({4}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, look at that player's hand. You may cast a spell from among those cards without paying its mana cost.

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, instead tap it, remove it from combat, and heal all damage on it.)

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Depths of Desire

Return target creature to its owner's hand. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Footlight Fiend

When this creature dies, it deals 1 damage to any target.

Neera, Wild Mage

Whenever you cast a spell, you may put it on the bottom of its owner's library. If you do, reveal cards from the top of your library until you reveal a nonland card. You may cast that card without paying its mana cost. Then put all revealed cards not cast this way on the bottom of your library in a random order. This ability triggers only once each turn.

Zevlor, Elturel Exile

Haste
{2}, {T}: When you next cast an instant or sorcery spell that targets only a single opponent or a single permanent an opponent controls this turn, for each other opponent, choose that player or a permanent they control, copy that spell, and the copy targets the chosen player or permanent.

Eater of Hope

Flying
{B}, Sacrifice another creature: Regenerate this creature.
{2}{B}, Sacrifice two other creatures: Destroy target creature.

Macabre Mockery

Put target creature card from an opponent's graveyard onto the battlefield under your control. It gets +2/+0 and gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Plargg and Nassari

At the beginning of your upkeep, each player exiles cards from the top of their library until they exile a nonland card. An opponent chooses a nonland card exiled this way. You may cast up to two spells from among the other cards exiled this way without paying their mana costs.

Deadly Derision

Destroy target creature or planeswalker. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Malevolent Whispers

Gain control of target creature until end of turn. Untap that creature. It gets +2/+0 and gains haste until end of turn.
Madness {3}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Swamp

Skulltap

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

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Ovika, Enigma Goliath

Flying
Ward—{3}, Pay 3 life.
Whenever you cast a noncreature spell, create X 1/1 red Phyrexian Goblin creature tokens, where X is the mana value of that spell. They gain haste until end of turn.

Island

Pyrrhic Blast

As an additional cost to cast this spell, sacrifice a creature.
Pyrrhic Blast deals damage equal to the sacrificed creature's power to any target. Draw a card.

Awaken the Sleeper

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. If it's equipped, you may destroy all Equipment attached to that creature.

Impulsive Pilferer

When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Encore {3}{R} ({3}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Emissary of Grudges

Flying, haste
As this creature enters, secretly choose an opponent.
Reveal the player you chose: Choose new targets for target spell or ability if it's controlled by the chosen player and if it targets you or a permanent you control. Activate only once.

Bloodmist Infiltrator

Whenever this creature attacks, you may sacrifice another creature. If you do, this creature can't be blocked this turn.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Ammit Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
Whenever an opponent casts a spell, put a -1/-1 counter on this creature.
Whenever this creature deals combat damage to a player, remove all -1/-1 counters from it.

Terramorphic Expanse

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Spark Harvest

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Destroy target creature or planeswalker.

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.

Corrupted Conviction

Blue Sun's Twilight

Gain control of target creature with mana value X or less. If X is 5 or more, create a token that's a copy of that creature.

Sol Ring

Mark of Mutiny

Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn. (It can attack and {T} this turn.)

Bankrupt in Blood

As an additional cost to cast this spell, sacrifice two creatures.
Draw three cards.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Sower of Discord

Flying
As this creature enters, choose two players.
Whenever damage is dealt to one of the chosen players, the other chosen player also loses that much life.

Norritt

{T}: Untap target blue creature.
{T}: Choose target non-Wall creature the active player has controlled continuously since the beginning of the turn. That creature attacks this turn if able. Destroy it at the beginning of the next end step if it didn't attack this turn. Activate only before attackers are declared.

Glistening Goremonger

When this creature dies, each opponent sacrifices an artifact or creature of their choice.

Pyretic Prankster

{3}{B/P}: Transform this creature. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.)

Pyretic Prankster // Glistening Goremonger

Lullmage's Domination

This spell costs {3} less to cast if it targets a creature whose controller has eight or more cards in their graveyard.
Gain control of target creature with mana value X.

Whisper, Blood Liturgist

{T}, Sacrifice two creatures: Return target creature card from your graveyard to the battlefield.

Catalyst Elemental

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Aphetto Alchemist

{T}: Untap target artifact or creature.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Nefarious Imp

Flying
Whenever one or more permanents you control leave the battlefield, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Demon of Catastrophes

As an additional cost to cast this spell, sacrifice a creature.
Flying, trample

Raphael, Fiendish Savior

Flying
Other Demons, Devils, Imps, and Tieflings you control get +1/+1 and have lifelink.
At the beginning of each end step, if a creature card was put into your graveyard from anywhere this turn, create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."

Baleful Ammit

Lifelink
When this creature enters, put a -1/-1 counter on target creature you control.

Rakdos Carnarium

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

Cadaver Imp

Flying
When this creature enters, you may return target creature card from your graveyard to your hand.

Morbid Curiosity

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw cards equal to the mana value of the sacrificed permanent.

Mountain

Mahadi, Emporium Master

At the beginning of your end step, create a Treasure token for each creature that died this turn. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Doom Blade

Wrangle

Gain control of target creature with power 4 or less until end of turn. Untap that creature. It gains haste until end of turn.

Goatnap

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. If that creature is a Goat, it also gets +3/+0 until end of turn.

Costly Plunder

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