Sol Ring

Bloodfell Caves

Bloodfell Caves enters tapped.
When Bloodfell Caves enters, you gain 1 life.
{T}: Add {B} or {R}.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Torch Fiend

{R}, Sacrifice Torch Fiend: Destroy target artifact.

Resourceful Return

Return target creature card from your graveyard to your hand. If you control an artifact, draw a card.

Swamp

Earth-Cult Elemental

Siege Monster — When Earth-Cult Elemental enters, roll a d20.
1—9 | Each player sacrifices a permanent.
10—19 | Each opponent sacrifices a permanent.
20 | Each opponent sacrifices two permanents.

Getting

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.)

Go for the Throat

Pitchburn Devils

When Pitchburn Devils dies, it deals 3 damage to any target.

Blood Money

Destroy all creatures. For each nontoken creature destroyed this way, you create a tapped Treasure token.

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 creature dies, it deals 1 damage to any target."

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Fetid Imp

Flying
{B}: Fetid Imp gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Evolving Wilds

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

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.

Raise Dead

Return target creature card from your graveyard to your hand.

Fall of the Hammer

Target creature you control deals damage equal to its power to another target creature.

Network Terminal

{T}: Add one mana of any color.
{1}, {T}, Tap another untapped artifact you control: Draw a card, then discard a card.

Wrack with Madness

Target creature deals damage to itself equal to its power.

Bothersome Quasit

Menace
Goaded creatures your opponents control can't block.
Whenever you cast a noncreature spell, goad target creature an opponent controls. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Bonecaller Cleric

{3}{B}, Sacrifice Bonecaller Cleric: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Cloudkill

All creatures get -X/-X until end of turn, where X is the greatest mana value of a commander you own on the battlefield or in the command zone.

Spawn of Rix Maadi

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.)

Dark Banishing

Destroy target nonblack creature. It can't be regenerated.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Commander's Sphere

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

Renegade Demon

Luxury Suite

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

Mountain

Bombard

Bombard deals 4 damage to target creature.

Murder

Drider

Reach
Whenever Drider deals combat damage to a player, create a 2/1 black Spider creature token with menace and reach.

Sigil of Myrkul

At the beginning of combat on your turn, mill a card. When you do, if there are four or more creature cards in your graveyard, put a +1/+1 counter on target creature you control and it gains deathtouch until end of turn. (To mill a card, put the top card of your library into your graveyard.)

Sivriss, Nightmare Speaker

{T}, Sacrifice another creature or an artifact: For each opponent, you mill a card, then return that card from your graveyard to your hand unless that player pays 3 life. (To mill a card, put the top card of your library into your graveyard.)
Choose a Background (You can have a Background as a second commander.)

Passageway Seer

Lifelink
When Passageway Seer enters, you take the initiative.
At the beginning of your end step, if you have the initiative, put a +1/+1 counter on Passageway Seer.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Festival Crasher

Whenever you cast an instant or sorcery spell, Festival Crasher gets +2/+0 until end of turn.

Bathe in Dragonfire

Bathe in Dragonfire deals 4 damage to target creature.

Thunderous Wrath

Thunderous Wrath deals 5 damage to any target.
Miracle {R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Command Tower

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

Lava Axe

Lava Axe deals 5 damage to target player or planeswalker.

Myrkul's Edict

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

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Cultist of the Absolute

Commander creatures you own get +3/+3 and have flying, deathtouch, "Ward—Pay 3 life," and "At the beginning of your upkeep, sacrifice a creature."

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Daggerclaw Imp

Feast of Dreams

Destroy target enchanted creature or enchantment creature.

Entropic Decay

Mill four cards. (Then exile this card. You may cast the creature later from exile.)

Gray Slaad

As long as there are four or more creature cards in your graveyard, Gray Slaad has menace and deathtouch.

Gray Slaad // Entropic Decay

Into the Night

It becomes night. Discard any number of cards, then draw that many cards plus one.

Cast Down

Mortuary Mire

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

Grim Hireling

Whenever one or more creatures you control deal combat damage to a player, create two Treasure tokens.
{B}, Sacrifice X Treasures: Target creature gets -X/-X until end of turn. Activate only as a sorcery.

Glistening Goremonger

When Glistening Goremonger dies, each opponent sacrifices an artifact or creature.

Pyretic Prankster

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

Pyretic Prankster // Glistening Goremonger

Defenestrate

Foul Imp

Flying
When Foul Imp enters, you lose 2 life.

Valor Singer

Combat Inspiration — At the beginning of combat on your turn, target creature you control gets +1/+0 until end of turn.

Brimstone Vandal

Menace (This creature can't be blocked except by two or more creatures.)
If it's neither day nor night, it becomes day as Brimstone Vandal enters.
Whenever day becomes night or night becomes day, Brimstone Vandal deals 1 damage to each opponent.

Demonic Stench

Each creature that blocked this turn gets -1/-1 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Hezrou

Whenever one or more creatures you control become blocked, each blocking creature gets -1/-1 until end of turn.

Hezrou // Demonic Stench

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

Chain Devil

Animate Chains — When Chain Devil enters, each player sacrifices a nontoken creature.

Hulking Devil

Dreadfeast Demon

Flying
At the beginning of your end step, sacrifice a non-Demon creature. If you do, create a token that's a copy of Dreadfeast Demon.

Volcanic Hammer

Volcanic Hammer deals 3 damage to any target.

Shelob, Dread Weaver

Whenever a nontoken creature an opponent controls dies, exile it.
{2}{B}, Put a creature card exiled with Shelob, Dread Weaver into its owner's graveyard: Put two +1/+1 counters on Shelob. Draw a card.
{X}{1}{B}: Put target creature card with mana value X exiled with Shelob onto the battlefield tapped under your control.

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 Rafter Demon enters, if its spectacle cost was paid, each opponent discards a card.

Call to the Void

Each player secretly chooses a creature they control and a creature they don't control. Then those choices are revealed. Destroy each creature chosen this way.

Frenzied Devils

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

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Cathartic Pyre

Choose one —
• Cathartic Pyre deals 3 damage to target creature or planeswalker.
• Discard up to two cards, then draw that many cards.