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.)

Rageform

When this enchantment enters, it becomes an Aura with enchant creature. Manifest the top card of your library and attach this enchantment to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Lotus Field

Hexproof
This land enters tapped.
When this land enters, sacrifice two lands.
{T}: Add three mana of any one color.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Shimmering Grotto

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

The Reaver Cleaver

Equipped creature gets +1/+1 and has trample and "Whenever this creature deals combat damage to a player or planeswalker, create that many Treasure tokens."
Equip {3}

Kwende, Pride of Femeref

Double strike
Creatures you control with first strike have double strike.

Plains

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Assemble the Legion

At the beginning of your upkeep, put a muster counter on this enchantment. Then create a 1/1 red and white Soldier creature token with haste for each muster counter on this enchantment.

Furycalm Snarl

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

Aurelia, the Warleader

Flying, vigilance, haste
Whenever Aurelia attacks for the first time each turn, untap all creatures you control. After this phase, there is an additional combat phase.

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Taurean Mauler

Changeling (This card is every creature type.)
Whenever an opponent casts a spell, you may put a +1/+1 counter on this creature.

Radiant Fountain

When this land enters, you gain 2 life.
{T}: Add {C}.

Anya, Merciless Angel

Flying
Anya gets +3/+3 for each opponent whose life total is less than half their starting life total.
As long as an opponent's life total is less than half their starting life total, Anya has indestructible.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Boros Garrison

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

Fury of the Horde

You may exile two red cards from your hand rather than pay this spell's mana cost.
Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Sol Ring

Starnheim Aspirant

Angel spells you cast cost {2} less to cast.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Fellwar Stone

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

Aurelia's Fury

Aurelia's Fury deals X damage divided as you choose among any number of targets. Tap each creature dealt damage this way. Players dealt damage this way can't cast noncreature spells this turn.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Oblivion Sower

When you cast this spell, target opponent exiles the top four cards of their library, then you may put any number of land cards that player owns from exile onto the battlefield under your control.

Angel of Jubilation

Flying
Other nonblack creatures you control get +1/+1.
Players can't pay life or sacrifice creatures to cast spells or activate abilities.

Entreat the Angels

Create X 4/4 white Angel creature tokens with flying.
Miracle {X}{W}{W} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Excalibur, Sword of Eden

This spell costs {X} less to cast, where X is the total mana value of historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)
Equipped creature gets +10/+0 and has vigilance.
Equip legendary creature {2}

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Aegis of the Gods

You have hexproof. (You can't be the target of spells or abilities your opponents control.)

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, this creature gets +5/+5 and has flying.

Great Train Heist

Spree (Choose one or more additional costs.)
+ {2}{R} — Untap all creatures you control. If it's your combat phase, there is an additional combat phase after this phase.
+ {2} — Creatures you control get +1/+0 and gain first strike until end of turn.
+ {R} — Choose target opponent. Whenever a creature you control deals combat damage to that player this turn, create a tapped Treasure token.

Fiery Confluence

Choose three. You may choose the same mode more than once.
• Fiery Confluence deals 1 damage to each creature.
• Fiery Confluence deals 2 damage to each opponent.
• Destroy target artifact.

Banishing Stroke

Put target artifact, creature, or enchantment on the bottom of its owner's library.
Miracle {W} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Hero's Blade

Equipped creature gets +3/+2.
Whenever a legendary creature you control enters, you may attach this Equipment to it.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Caduceus, Staff of Hermes

Equipped creature has lifelink.
As long as you have 30 or more life, equipped creature gets +5/+5 and has indestructible and "Prevent all damage that would be dealt to this creature."
Equip {W}{W}

Gisela, Blade of Goldnight

Flying, first strike
If a source would deal damage to an opponent or a permanent an opponent controls, that source deals double that damage to that player or permanent instead.
If a source would deal damage to you or a permanent you control, prevent half that damage, rounded up.

Twinflame Tyrant

Flying
If a source you control would deal damage to an opponent or a permanent an opponent controls, it deals double that damage instead.

Heartflame Slash

Heartflame Slash deals 3 damage to any target. (Then exile this card. You may cast the creature later from exile.)

Heartflame Duelist

Instant and sorcery spells you control have lifelink.

Heartflame Duelist // Heartflame Slash

Spectator Seating

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

Clifftop Retreat

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

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Arcane Signet

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

Avacyn, Angel of Hope

Flying, vigilance, indestructible
Other permanents you control have indestructible.

Justice Strike

Target creature deals damage to itself equal to its power.

The Spear of Leonidas

Whenever equipped creature attacks, choose one —
• Bull Rush — It gains double strike until end of turn.
• Summon — Create Phobos, a legendary 3/2 red Horse creature token.
• Revelation — Discard two cards, then draw two cards.
Equip {2}

Sunspine Lynx

Players can't gain life.
Damage can't be prevented.
When this creature enters, it deals damage to each player equal to the number of nonbasic lands that player controls.

Mountain

Angel of the Dire Hour

Flash
Flying
When this creature enters, if you cast it from your hand, exile all attacking creatures.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Faith's Fetters

Enchant permanent
When this Aura enters, you gain 4 life.
Enchanted permanent can't attack or block, and its activated abilities can't be activated unless they're mana abilities.

Baneslayer Angel

Flying, first strike, lifelink, protection from Demons and from Dragons

Dolmen Gate

Prevent all combat damage that would be dealt to attacking creatures you control.

Pearl Medallion

White spells you cast cost {1} less to cast.

Stranglehold

Your opponents can't search libraries.
If an opponent would begin an extra turn, that player skips that turn instead.

Battlegrace Angel

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, it gains lifelink until end of turn.

Angel of Serenity

Flying
When this creature enters, you may exile up to three other target creatures from the battlefield and/or creature cards from graveyards.
When this creature leaves the battlefield, return the exiled cards to their owners' hands.

Descend upon the Sinful

Exile all creatures.
Delirium — Create a 4/4 white Angel creature token with flying if there are four or more card types among cards in your graveyard.

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Drifting Meadow

This land enters tapped.
{T}: Add {W}.
Cycling {2} ({2}, Discard this card: Draw a card.)

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Valorous Stance

Choose one —
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
• Destroy target creature with toughness 4 or greater.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put this artifact on top of its owner's library.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Aurelia, the Law Above

Flying, vigilance, haste
Whenever a player attacks with three or more creatures, you draw a card.
Whenever a player attacks with five or more creatures, Aurelia deals 3 damage to each of your opponents and you gain 3 life.

Haystack

{2}, {T}: Target creature you control phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)

Secluded Steppe

This land enters tapped.
{T}: Add {W}.
Cycling {W} ({W}, Discard this card: Draw a card.)

Command Tower

Nahiri's Machinations

At the beginning of combat on your turn, target creature you control gains indestructible until end of turn.
{1}{R}: This enchantment deals 1 damage to target blocking creature.

Gratuitous Violence

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

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Giada, Font of Hope

Flying, vigilance
Each other Angel you control enters with an additional +1/+1 counter on it for each Angel you already control.
{T}: Add {W}. Spend this mana only to cast an Angel spell.

Sephara, Sky's Blade

You may pay {W} and tap four untapped creatures you control with flying rather than pay this spell's mana cost.
Flying, lifelink
Other creatures you control with flying have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Breath of Life

Return target creature card from your graveyard to the battlefield.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is this creature's power.

Blacksmith's Talent

(Gain the next level as a sorcery to add its ability.)
When this Class enters, create a colorless Equipment artifact token named Sword with "Equipped creature gets +1/+1" and equip {2}.
{2}{R}: Level 2
At the beginning of combat on your turn, attach target Equipment you control to up to one target creature you control.
{3}{R}: Level 3
During your turn, equipped creatures you control have double strike and haste.

Shattered Angel

Flying
Whenever a land an opponent controls enters, you may gain 3 life.

Restless Bivouac

This land enters tapped.
{T}: Add {R} or {W}.
{1}{R}{W}: This land becomes a 2/2 red and white Ox creature until end of turn. It's still a land.
Whenever this land attacks, put a +1/+1 counter on target creature you control.

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Delina, Wild Mage

Whenever Delina attacks, choose target creature you control, then roll a d20.
1—14 | Create a tapped and attacking token that's a copy of that creature, except it's not legendary and it has "At end of combat, exile this token."
15—20 | Create one of those tokens. You may roll again.

High Noon

Each player can't cast more than one spell each turn.
{4}{R}, Sacrifice this enchantment: It deals 5 damage to any target.

Sacred Foundry

({T}: Add {R} or {W}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.