Hobblefiend

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
{1}, Sacrifice another creature: Put a +1/+1 counter on this creature.

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.

The Beast, Deathless Prince

When you cast this spell, gain control of target creature until end of turn. Untap it. It gains menace and haste until end of turn.
The Beast enters tapped with six stun counters on it. (If it would become untapped, remove a stun counter from it instead.)
Whenever a creature deals combat damage to its owner, untap The Beast and draw a card.

Orca, Siege Demon

Trample
Whenever another creature dies, put a +1/+1 counter on Orca.
When Orca dies, it deals damage equal to its power divided as you choose among any number of targets.

Havoc Jester

Whenever you sacrifice a permanent, this creature deals 1 damage to any target.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Back for Seconds

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Return up to two target creature cards from your graveyard to your hand. If this spell was bargained, you may put one of those cards with mana value 4 or less onto the battlefield instead of putting it into your hand.

Devils' Playground

Create four 1/1 red Devil creature tokens. They have "When this token dies, it deals 1 damage to any target."

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

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

Warehouse Thief

{2}, {T}, Sacrifice an artifact or creature: Exile the top card of your library. Until the end of your next turn, you may play that card.

Bind Spirit

Return target creature card from your graveyard to your hand. (Then exile this card. You may cast the artifact later from exile.)

Ghost Lantern

Whenever a creature you control dies, put a +1/+1 counter on equipped creature.
Equip {1}

Ghost Lantern // Bind Spirit

Herald of Slaanesh

Locus of Slaanesh — Demon spells you cast cost {2} less to cast.
Other Demons you control have haste.

Spiteful Prankster

During your turn, this creature has first strike.
Whenever another creature dies, this creature deals 1 damage to target player or planeswalker.

Tibalt's Rager

When this creature dies, it deals 1 damage to any target.
{1}{R}: This creature gets +2/+0 until end of turn.

The Balrog, Durin's Bane

This spell costs {1} less to cast for each permanent sacrificed this turn.
Haste
The Balrog can't be blocked except by legendary creatures.
When The Balrog dies, destroy target artifact or creature an opponent controls.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Warlock Class

(Gain the next level as a sorcery to add its ability.)
At the beginning of your end step, if a creature died this turn, each opponent loses 1 life.
{1}{B}: Level 2
When this Class becomes level 2, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
{6}{B}: Level 3
At the beginning of your end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Demon

Hurl Through Hell

Exile target creature. Until the end of your next turn, you may cast that card and you may spend mana as though it were mana of any color to cast that spell.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage instead.

Gibbering Fiend

When this creature enters, it deals 1 damage to each opponent.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, this creature deals 1 damage to that player.

Torch Fiend

{R}, Sacrifice this creature: Destroy target artifact.

Hero's Downfall

Kardur's Vicious Return

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — You may sacrifice a creature. When you do, this Saga deals 3 damage to any target.
II — Each player discards a card.
III — Return target creature card from your graveyard to the battlefield. Put a +1/+1 counter on it. It gains haste until your next turn.

Corrupted Conviction

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

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Village Rites

Body Dropper

Whenever you sacrifice another creature, put a +1/+1 counter on this creature.
{B}{R}, Sacrifice another creature: This creature gains menace until end of turn. (It can't be blocked except by two or more creatures.)

Garna, Bloodfist of Keld

Whenever another creature you control dies, draw a card if it was attacking. Otherwise, Garna deals 1 damage to each opponent.

Devil

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

Dance with Devils

Create two 1/1 red Devil creature tokens. They have "When this token dies, it deals 1 damage to any target."

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.)

Bedevil

Destroy target artifact, creature, or planeswalker.

Zariel, Archduke of Avernus

+1: Creatures you control get +1/+0 and gain haste until end of turn.
0: Create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."
−6: You get an emblem with "At the end of the first combat phase on your turn, untap target creature you control. After this phase, there is an additional combat phase."

Arcane Signet

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

Diabolic Tutor

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

Witty Roastmaster

Alliance — Whenever another creature you control enters, this creature deals 1 damage to each opponent.

Kardur, Doomscourge

When Kardur enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Bone Shards

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

Thraxodemon

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

Bloodsoaked Altar

{T}, Pay 2 life, Discard a card, Sacrifice a creature: Create a 5/5 black Demon creature token with flying. Activate only as a sorcery.

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.")

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."

Karazikar, the Eye Tyrant

Whenever you attack a player, tap target creature that player controls and goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever an opponent attacks another one of your opponents, you and the attacking player each draw a card and lose 1 life.

Charmbreaker Devils

At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, this creature gets +4/+0 until end of turn.

Too Greedily, Too Deep

Put target creature card from a graveyard onto the battlefield under your control. That creature deals damage equal to its power to each other creature.

Lorcan, Warlock Collector

Flying
Whenever a creature card is put into an opponent's graveyard from anywhere, you may pay life equal to its mana value. If you do, put it onto the battlefield under your control. It's a Warlock in addition to its other types.
If a Warlock you control would die, exile it instead.

Demon of Catastrophes

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

Viscera Seer

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

The Tomb of Aclazotz

(Transforms from Tarrian's Journal.)
{T}: Add {B}.
{T}: You may cast a creature spell from your graveyard this turn. If you do, it enters with a finality counter on it and is a Vampire in addition to its other types. (If a creature with a finality counter on it would die, exile it instead.)

Tarrian's Journal

{T}, Sacrifice another artifact or creature: Draw a card. Activate only as a sorcery.
{2}, {T}, Discard your hand: Transform Tarrian's Journal.

Tarrian's Journal // The Tomb of Aclazotz

Hellrider

Haste
Whenever a creature you control attacks, this creature deals 1 damage to the player or planeswalker it's attacking.

Orcus, Prince of Undeath

Flying, trample
When Orcus enters, choose one —
• Each other creature gets -X/-X until end of turn. You lose X life.
• Return up to X target creature cards with total mana value X or less from your graveyard to the battlefield. They gain haste until end of turn.

Altar's Reap

Wildfire Devils

When this creature enters and at the beginning of your upkeep, choose a player at random. That player exiles an instant or sorcery card from their graveyard. Copy that card. You may cast the copy without paying its mana cost.

Burn Down the House

Choose one —
• Burn Down the House deals 5 damage to each creature and each planeswalker.
• Create three 1/1 red Devil creature tokens with "When this token dies, it deals 1 damage to any target." They gain haste until end of turn.

Braids's Frightful Return

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — You may sacrifice a creature. If you do, each opponent discards a card.
II — Return target creature card from your graveyard to your hand.
III — Target opponent may sacrifice a nonland, nontoken permanent of their choice. If they don't, they lose 2 life and you draw a card.

Hidetsugu, Devouring Chaos

{B}, Sacrifice a creature: Scry 2.
{2}{R}, {T}: Exile the top card of your library. You may play that card this turn. When you exile a nonland card this way, Hidetsugu deals damage equal to the exiled card's mana value to any target.

Mechanized Warfare

If a red or artifact source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Showstopper

Until end of turn, creatures you control gain "When this creature dies, it deals 2 damage to target creature an opponent controls."

Sin Prodder

Menace
At the beginning of your upkeep, reveal the top card of your library. Any opponent may have you put that card into your graveyard. If a player does, this creature deals damage to that player equal to that card's mana value. Otherwise, put that card into your hand.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Devilish Valet

Trample, haste
Alliance — Whenever another creature you control enters, double this creature's power until end of turn.