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.)

Getting

Bruse Tarl, Boorish Herder

Whenever Bruse Tarl enters or attacks, target creature you control gains double strike and lifelink until end of turn.
Partner (You can have two commanders if both have partner.)

Indatha Triome

({T}: Add {W}, {B}, or {G}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Seasons Past

Return any number of cards with different mana values from your graveyard to your hand. Put Seasons Past on the bottom of its owner's library.

Gollum, Obsessed Stalker

Skulk (This creature can't be blocked by creatures with greater power.)
At the beginning of your end step, each opponent dealt combat damage this game by a creature named Gollum, Obsessed Stalker loses life equal to the amount of life you gained this turn.

Timbercrown Pathway

Cragcrown Pathway

Cragcrown Pathway // Timbercrown Pathway

Yoshimaru, Ever Faithful

Whenever another legendary permanent you control enters, put a +1/+1 counter on Yoshimaru.
Partner (You can have two commanders if both have partner.)

Clifftop Retreat

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

Elvish Reclaimer

This creature gets +2/+2 as long as there are three or more land cards in your graveyard.
{2}, {T}, Sacrifice a land: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Annie Joins Up

When Annie Joins Up enters, it deals 5 damage to target creature or planeswalker an opponent controls.
If a triggered ability of a legendary creature you control triggers, that ability triggers an additional time.

Umori, the Collector

Companion — Each nonland card in your starting deck shares a card type. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
As Umori enters, choose a card type.
Spells you cast of the chosen type cost {1} less to cast.

Windswept Heath

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Adventurers' Guildhouse

Green legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Rune-Tail's Essence

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

Rune-Tail, Kitsune Ascendant

When you have 30 or more life, flip Rune-Tail.

Rune-Tail, Kitsune Ascendant // Rune-Tail's Essence

Chromatic Lantern

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

Blasphemous Act

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

Saskia the Unyielding

Vigilance, haste
As Saskia enters, choose a player.
Whenever a creature you control deals combat damage to a player, it deals that much damage to the chosen player.

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.

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Guenhwyvar

The Gaffer

At the beginning of each end step, if you gained 3 or more life this turn, draw a card.

Avacyn's Memorial

Indestructible
Other legendary permanents you control have indestructible.

Breena, the Demagogue

Flying
Whenever a player attacks one of your opponents, if that opponent has more life than another of your opponents, that attacking player draws a card and you put two +1/+1 counters on a creature you control.

Tymna the Weaver

Lifelink
At the beginning of each of your postcombat main phases, you may pay X life, where X is the number of opponents that were dealt combat damage this turn. If you do, draw X cards.
Partner (You can have two commanders if both have partner.)

Sylvan Scrying

Search your library for a land card, reveal it, put it into your hand, then shuffle.

Reki, the History of Kamigawa

Whenever you cast a legendary spell, draw a card.

Karlov of the Ghost Council

Whenever you gain life, put two +1/+1 counters on Karlov.
{W}{B}, Remove six +1/+1 counters from Karlov: Exile target creature.

Rugged Prairie

{T}: Add {C}.
{R/W}, {T}: Add {R}{R}, {R}{W}, or {W}{W}.

Woodland Cemetery

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

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Isolated Chapel

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

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

Court of Bounty

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, you may put a land card from your hand onto the battlefield. If you're the monarch, instead you may put a creature or land card from your hand onto the battlefield.

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Surrak and Goreclaw

Trample
Other creatures you control have trample.
Whenever another nontoken creature you control enters, put a +1/+1 counter on it. It gains haste until end of turn.

Commissar Severina Raine

Leading from the Front — Whenever Commissar Severina Raine attacks, each opponent loses X life, where X is the number of other attacking creatures.
Summary Execution — {2}, Sacrifice another creature: You gain 2 life and draw a card.

Knight of the Reliquary

This creature gets +1/+1 for each land card in your graveyard.
{T}, Sacrifice a Forest or Plains: Search your library for a land card, put it onto the battlefield, then shuffle.

Gorm the Great

Partner with Virtus the Veiled (When this creature enters, target player may put Virtus into their hand from their library, then shuffle.)
Vigilance
Gorm must be blocked if able, and Gorm must be blocked by two or more creatures if able.

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Cathedral of Serra

White legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Ziatora's Proving Ground

({T}: Add {B}, {R}, or {G}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)

Sowing Mycospawn

Devoid (This card has no color.)
Kicker {1}{C} (You may pay an additional {1}{C} as you cast this spell.)
When you cast this spell, search your library for a land card, put it onto the battlefield, then shuffle.
When you cast this spell, if it was kicked, exile target land.

Boros Signet

Fire-Lit Thicket

{T}: Add {C}.
{R/G}, {T}: Add {R}{R}, {R}{G}, or {G}{G}.

Samut, Voice of Dissent

Flash
Double strike, vigilance, haste
Other creatures you control have haste.
{W}, {T}: Untap another target creature.

Arcane Signet

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

Yargle and Multani

Vault of Champions

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

Descent into Avernus

At the beginning of your upkeep, put two descent counters on this enchantment. Then each player creates X Treasure tokens and this enchantment deals X damage to each player, where X is the number of descent counters on this enchantment.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Vivien, Champion of the Wilds

You may cast creature spells as though they had flash.
+1: Until your next turn, up to one target creature gains vigilance and reach.
−2: Look at the top three cards of your library. Exile one face down and put the rest on the bottom of your library in any order. For as long as it remains exiled, you may cast it if it's a creature spell.

Undergrowth Stadium

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

Plains

Don't Have

Gladiolus Amicitia

When Gladiolus Amicitia enters, search your library for a land card, put it onto the battlefield tapped, then shuffle.
Landfall — Whenever a land you control enters, another target creature you control gets +2/+2 and gains trample until end of turn.

Urza's Cave

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Rakdos Signet

Command Tower

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Golgari Signet

Mountain

Unholy Citadel

Black legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Time of Need

Search your library for a legendary creature card, reveal it, put it into your hand, then shuffle.

Gideon, Battle-Forged

+2: Up to one target creature an opponent controls attacks Gideon during its controller's next turn if able.
+1: Until your next turn, target creature gains indestructible. Untap that creature.
0: Until end of turn, Gideon becomes a 4/4 Human Soldier creature with indestructible that's still a planeswalker. Prevent all damage that would be dealt to him this turn.

Kytheon, Hero of Akros

At end of combat, if Kytheon and at least two other creatures attacked this combat, exile Kytheon, then return him to the battlefield transformed under his owner's control.
{2}{W}: Kytheon gains indestructible until end of turn.

Kytheon, Hero of Akros // Gideon, Battle-Forged

Graven Cairns

{T}: Add {C}.
{B/R}, {T}: Add {B}{B}, {B}{R}, or {R}{R}.

Ragavan, Nimble Pilferer

Whenever Ragavan deals combat damage to a player, create a Treasure token and exile the top card of that player's library. Until end of turn, you may cast that card.
Dash {1}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Exotic Orchard

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

Jetmir, Nexus of Revels

Creatures you control get +1/+0 and have vigilance as long as you control three or more creatures.
Creatures you control also get +1/+0 and have trample as long as you control six or more creatures.
Creatures you control also get +1/+0 and have double strike as long as you control nine or more creatures.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Spectator Seating

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

Sunpetal Grove

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

Tyranid

General Marhault Elsdragon

Whenever a creature you control becomes blocked, it gets +3/+3 until end of turn for each creature blocking it.

Rienne, Angel of Rebirth

Flying
Other multicolored creatures you control get +1/+0.
Whenever another multicolored creature you control dies, return it to its owner's hand at the beginning of the next end step.

Primevals' Glorious Rebirth

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Return all legendary permanent cards from your graveyard to the battlefield.

Lure

Enchant creature
All creatures able to block enchanted creature do so.

Dihada, Binder of Wills

+2: Up to one target legendary creature gains vigilance, lifelink, and indestructible until your next turn.
−3: Reveal the top four cards of your library. Put any number of legendary cards from among them into your hand and the rest into your graveyard. Create a Treasure token for each card put into your graveyard this way.
−11: Gain control of all nonland permanents until end of turn. Untap them. They gain haste until end of turn.
Dihada, Binder of Wills can be your commander.

Vraska Joins Up

When Vraska Joins Up enters, put a deathtouch counter on each creature you control.
Whenever a legendary creature you control deals combat damage to a player, draw a card.

Overgrown Farmland

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Tome of Legends

This artifact enters with a page counter on it.
Whenever your commander enters or attacks, put a page counter on this artifact.
{1}, {T}, Remove a page counter from this artifact: Draw a card.

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.

Boulderloft Pathway

Branchloft Pathway

Branchloft Pathway // Boulderloft Pathway

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.)

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Shaman of Forgotten Ways

{T}: Add two mana in any combination of colors. Spend this mana only to cast creature spells.
Formidable — {9}{G}{G}, {T}: Each player's life total becomes the number of creatures they control. Activate only if creatures you control have total power 8 or greater.

Captain Sisay

{T}: Search your library for a legendary card, reveal that card, put it into your hand, then shuffle.

Urza's Ruinous Blast

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Exile all nonland permanents that aren't legendary.

Expedited Inheritance

Whenever a creature is dealt damage, its controller may exile that many cards from the top of their library. They may play those cards until the end of their next turn.

Shadow in the Warp

The first creature spell you cast each turn costs {2} less to cast.
Whenever an opponent casts their first noncreature spell each turn, this enchantment deals 2 damage to that player.

Flowering of the White Tree

Legendary creatures you control get +2/+1 and have ward {1}.
Nonlegendary creatures you control get +1/+1.

The Kenriths' Royal Funeral

When The Kenriths' Royal Funeral enters, exile up to two target legendary creature cards from your graveyard. You draw X cards and you lose X life, where X is the greatest mana value among cards exiled this way.
Legendary spells you cast cost {1} less to cast for each card exiled with The Kenriths' Royal Funeral.

Dragonskull Summit

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. This land deals 1 damage to you.

Rite of Passage

Whenever a creature you control is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Bastion Protector

Commander creatures you control get +2/+2 and have indestructible.