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.

Rakdos the Defiler

Flying, trample
Whenever Rakdos attacks, sacrifice half the non-Demon permanents you control, rounded up.
Whenever Rakdos deals combat damage to a player, that player sacrifices half the non-Demon permanents they control of their choice, rounded up.

Blasphemous Edict

You may pay {B} rather than pay this spell's mana cost if there are thirteen or more creatures on the battlefield.
Each player sacrifices thirteen creatures of their choice.

Dance with Devils

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

Indulgent Tormentor

Flying
At the beginning of your upkeep, draw a card unless target opponent sacrifices a creature of their choice or pays 3 life.

Rakdos Guildgate

This land enters tapped.
{T}: Add {B} or {R}.

Rakdos Cluestone

{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice this artifact: Draw 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.)

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Charcoal Diamond

This artifact enters tapped.
{T}: Add {B}.

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."

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."

Infernal Captor

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, gain control of target artifact or creature until end of turn. Untap that permanent. It gains haste until end of turn.

Village Rites

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

Rakdos Headliner

Haste
Echo—Discard a card. (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

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.

Malfegor

Flying
When Malfegor enters, discard your hand. Each opponent sacrifices a creature of their choice for each card discarded this way.

Rakdos Cackler

Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

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.

Underworld Dreams

Whenever an opponent draws a card, this enchantment deals 1 damage to that player.

Lagomos, Hand of Hatred

At the beginning of combat on your turn, create a 2/1 red Elemental creature token with trample and haste. Sacrifice it at the beginning of the next end step.
{T}: Search your library for a card, put it into your hand, then shuffle. Activate only if five or more creatures died this turn.

Profane Memento

Whenever a creature card is put into an opponent's graveyard from anywhere, you gain 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

Forge Devil

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

Palantír of Orthanc

At the beginning of your end step, put an influence counter on Palantír of Orthanc and scry 2. Then target opponent may have you draw a card. If that player doesn't, you mill X cards, where X is the number of influence counters on Palantír of Orthanc, and that player loses life equal to the total mana value of those cards.

Rakdos Carnarium

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

Guildsworn Prowler

Deathtouch
When this creature dies, if it wasn't blocking, draw a card.

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.

Fell Beast of Mordor

Flying
Devour 1 (As this creature enters, you may sacrifice any number of creatures. It enters with that many +1/+1 counters on it.)
Whenever this creature enters or attacks, target opponent loses X life and you gain X life, where X is the number of +1/+1 counters on it.

Judith, the Scourge Diva

Other creatures you control get +1/+0.
Whenever a nontoken creature you control dies, Judith deals 1 damage to any target.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Barad-dûr

Barad-dûr enters tapped unless you control a legendary creature.
{T}: Add {B}.
{X}{X}{B}, {T}: Amass Orcs X. Activate only if a creature died this turn.

Dragon Cultist

Commander creatures you own have "At the beginning of your end step, if a source you controlled dealt 5 or more damage this turn, create a 4/4 red Dragon creature token with flying."

Sire of Insanity

At the beginning of each end step, each player discards their hand.

Smoldering Marsh

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

Commander's Sphere

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

Rakdos, Lord of Riots

You can't cast Rakdos unless an opponent lost life this turn.
Flying, trample
Creature spells you cast cost {1} less to cast for each 1 life your opponents have lost this turn.

Murder

Hoard Robber

Whenever this 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.")

Archfiend of Sorrows

Flying
When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Unearth {3}{B}{B} ({3}{B}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

Mountain

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Chain Devil

Animate Chains — When this creature enters, each player sacrifices a nontoken creature of their choice.

Mount Doom

{T}, Pay 1 life: Add {B} or {R}.
{1}{B}{R}, {T}: Mount Doom deals 1 damage to each opponent.
{5}{B}{R}, {T}, Sacrifice Mount Doom and a legendary artifact: Choose up to two creatures, then destroy the rest. Activate only as a sorcery.

Swamp

Tyrannize

Target player discards their hand unless they pay 7 life.

Ashnod's Altar

Jagged Barrens

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {B} or {R}.

Blight Keeper

Flying
{7}{B}, {T}, Sacrifice this creature: Target opponent loses 4 life and you gain 4 life.

Gravepurge

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Flayer of the Hatebound

Undying (When this creature 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.)
Whenever this creature or another creature enters from your graveyard, that creature deals damage equal to its power to any target.

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Tramway Station

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

Dark Ritual

Liliana Vess

+1: Target player discards a card.
−2: Search your library for a card, then shuffle and put that card on top.
−8: Put all creature cards from all graveyards onto the battlefield under your control.

Forge Boss

Whenever you sacrifice one or more other creatures, this creature deals 2 damage to each opponent. This ability triggers only once each 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.

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Cloak of the Bat

Equipped creature has flying and haste.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Altar's Reap

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

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.")

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.

Pack Attack

Attacking creatures get +X/+0 until end of turn, where X is the number of players being attacked.
Draw a card.

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.

Lord of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than this creature. If you can't, this creature deals 7 damage to you.

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.

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}.

Myrkul's Edict

Roll a d20.
1—9 | Choose an opponent. That player sacrifices a creature of their choice.
10—19 | Each opponent sacrifices a creature of their choice.
20 | Each opponent sacrifices a creature with the greatest power among creatures that player controls.

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.

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.

In Thrall to the Pit

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. If this spell was kicked, sacrifice that creature at the beginning of the next end step.

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.

Mayhem Devil

Whenever a player sacrifices a permanent, this creature deals 1 damage to any target.