Spark Reaper

{3}, Sacrifice a creature or planeswalker: You gain 1 life and draw a card.

Mountain

Goldvein Pick

Equipped creature gets +1/+1.
Whenever equipped creature deals combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Demonic Taskmaster

Flying
At the beginning of your upkeep, sacrifice a creature other than this creature.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on this creature.

Popular Entertainer

Commander creatures you own have "Whenever one or more creatures you control deal combat damage to a player, goad target creature that player controls." (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Gixian Infiltrator

Whenever you sacrifice another permanent, put a +1/+1 counter on this creature.

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.)

Etched Familiar

When this creature dies, each opponent loses 2 life and you gain 2 life.

Executioner's Hood

Equipped creature has intimidate. (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Dreg Recycler

{T}, Sacrifice an artifact or creature: Each opponent loses 1 life and you gain 1 life.

Mirkwood Bats

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

Doom Blade

Industrial Advancement

At the beginning of your end step, you may sacrifice a creature. If you do, look at the top X cards of your library, where X is that creature's mana value. You may put a creature card from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Falkenrath Noble

Flying
Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Gibbering Barricade

Defender
{2}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Gnawing Zombie

{1}{B}, Sacrifice a creature: Target player loses 1 life and you gain 1 life.

Heckling Fiends

{2}{R}: Target creature attacks this turn if able.

Spiteful Banditry

When this enchantment enters, it deals X damage to each creature.
Whenever one or more creatures your opponents control die, you create a Treasure token. This ability triggers only once each turn.

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."

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

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."

The Autonomous Furnace

This land enters tapped.
{T}: Add {R}.
{1}{R}, {T}, Sacrifice this land: Draw a card.

Disciple of Griselbrand

{1}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Juri, Master of the Revue

Whenever you sacrifice a permanent, put a +1/+1 counter on Juri.
When Juri dies, it deals damage equal to its power to any target.

Improvised Club

As an additional cost to cast this spell, sacrifice an artifact or creature.
Improvised Club deals 4 damage to any target.

Skeleton Archer

When this creature enters, 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."

Guild Artisan

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, you create two Treasure tokens." (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Pitchburn Devils

When this creature dies, it deals 3 damage to any target.

Mortuary Mire

This land enters tapped.
When this land enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Umbral Mantle

Equipped creature has "{3}, {Q}: This creature gets +2/+2 until end of turn." ({Q} is the untap symbol.)
Equip {0}

Witch's Cauldron

{1}{B}, {T}, Sacrifice a creature: You gain 1 life and draw a card.

Foreboding Ruins

As this land enters, you may reveal a Swamp or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {B} or {R}.

Bronze Sword

Equipped creature gets +2/+0.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Hazardous Blast

Hazardous Blast deals 1 damage to each creature your opponents control. Creatures your opponents control can't block this turn.

Murder

Vanquisher's Axe

Equipped creature gets +2/+0.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Swamp

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Street Urchin

Commander creatures you own have "{1}, Sacrifice another creature or an artifact: This creature deals 1 damage to any target."

Blaze

Bedevil

Destroy target artifact, creature, or planeswalker.

Gutless Ghoul

{1}, Sacrifice a creature: You gain 2 life.

Black Market

Whenever a creature dies, put a charge counter on this enchantment.
At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Vampire Spawn

When this creature enters, each opponent loses 2 life and you gain 2 life.

Curse of Shaken Faith

Enchant player
Whenever enchanted player casts a spell other than the first spell they cast each turn or copies a spell, this Aura deals 2 damage to them.

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Shrapnel Slinger

When this creature enters, you may sacrifice a creature. When you do, destroy target artifact an opponent controls.

Voracious Vermin

When this creature enters, create a 1/1 black Rat creature token with "This token can't block."
Whenever another creature you control dies, put a +1/+1 counter on this creature.

Ichor Shade

At the beginning of your end step, if an artifact or creature was put into a graveyard from the battlefield this turn, put a +1/+1 counter on this creature.

Thriving Moor

This land enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Storm King's Thunder

When you next cast an instant or sorcery spell this turn, copy that spell X times. You may choose new targets for the copies.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Luxury Suite

This land enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Severed Strands

As an additional cost to cast this spell, sacrifice a creature.
You gain life equal to the sacrificed creature's toughness. Destroy target creature an opponent controls.

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.

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

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.

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.

Forge Devil

When this creature enters, it deals 1 damage to target creature and 1 damage to you.

Nahiri's Sacrifice

As an additional cost to cast this spell, sacrifice an artifact or creature with mana value X.
Nahiri's Sacrifice deals X damage divided as you choose among any number of target creatures.

Scalding Devil

{2}{R}: This creature deals 1 damage to target player or planeswalker.

Sol Ring

Run Amok

Target attacking creature gets +3/+3 and gains trample until end of turn.

Go for the Throat

Ob Nixilis, the Adversary

Casualty X. The copy isn't legendary and has starting loyalty X. (As you cast this spell, you may sacrifice a creature with power X. When you do, copy this spell. The copy becomes a token.)
+1: Each opponent loses 2 life unless they discard a card. If you control a Demon or Devil, you gain 2 life.
−2: Create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."
−7: Target player draws seven cards and loses 7 life.

Zurzoth, Chaos Rider

Whenever an opponent draws their first card each turn, if it's not their turn, you create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."
Whenever one or more Devils you control attack one or more players, you and those players each draw a card, then discard a card at random.

Frenzied Devils

Haste
Whenever you cast a noncreature spell, this creature gets +2/+2 until end of turn.

Devour Flesh

Target player sacrifices a creature of their choice, then gains life equal to that creature's toughness.

Bloodfell Caves

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

Serrated Scorpion

When this creature dies, it deals 2 damage to each opponent and you gain 2 life.

Corrupted Conviction

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

Spikeshot Goblin

{R}, {T}: This creature deals damage equal to its power to any target.

Reign of the Pit

Each player sacrifices a creature of their choice. Create an X/X black Demon creature token with flying, where X is the total power of the creatures sacrificed this way.

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Sengir Connoisseur

Flying
Whenever one or more other creatures die, put a +1/+1 counter on this creature. This ability triggers only once each turn.

Arcane Signet

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

Bone Splinters

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

The Dross Pits

This land enters tapped.
{T}: Add {B}.
{1}{B}, {T}, Sacrifice this land: Draw a card.

Torch Fiend

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

Vraan, Executioner Thane

Whenever one or more other creatures you control die, each opponent loses 2 life and you gain 2 life. This ability triggers only once each turn.