Caves of Koilos

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

Mountain

Angrath's Marauders

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

Elder Arthur Maxson

Creature tokens you control have training. (Whenever a creature token you control attacks with another creature with greater power, put a +1/+1 counter on that token.)
Blind Betrayal — Sacrifice another creature: Elder Arthur Maxson gains indestructible until end of turn.

Colonel Autumn

Lifelink
Exploit (When this creature enters, you may sacrifice a creature.)
Other legendary creatures you control have exploit.
Whenever a creature you control exploits a creature, put a +1/+1 counter on each creature you control.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Outlaws' Merriment

At the beginning of your upkeep, choose one at random. Create a red and white creature token with those characteristics.
• 3/1 Human Warrior with trample and haste.
• 2/1 Human Cleric with lifelink and haste.
• 1/2 Human Rogue with haste and "When this token enters, it deals 1 damage to any target."

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Village Rites

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

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Chromatic Lantern

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

Fervent Charge

Whenever a creature you control attacks, it gets +2/+2 until end of turn.

Securitron Squadron

Squad {3} (As an additional cost to cast this spell, you may pay {3} any number of times. When this creature enters, create that many tokens that are copies of it.)
Vigilance
Whenever a creature token you control enters, put a +1/+1 counter on it.

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.

Arcane Signet

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

Mayhem Devil

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

Rakdos Signet

Lightning Greaves

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

Rugged Prairie

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

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Dark Ritual

Alesha, Who Laughs at Fate

First strike
Whenever Alesha attacks, put a +1/+1 counter on it.
Raid — At the beginning of your end step, if you attacked this turn, return target creature card with mana value less than or equal to Alesha's power from your graveyard to the battlefield.

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Infestation Sage

When this creature dies, create a 1/1 black and green Insect creature token with flying.

Windbrisk Heights

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This land enters tapped.
{T}: Add {W}.
{W}, {T}: You may play the exiled card without paying its mana cost if you attacked with three or more creatures this turn.

Cover of Darkness

As this enchantment enters, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Arabella, Abandoned Doll

Whenever Arabella attacks, it deals X damage to each opponent and you gain X life, where X is the number of creatures you control with power 2 or less.

Command Tower

Sacred Foundry

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

Talisman of Indulgence

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

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Battle of Hoover Dam

As this enchantment enters, choose NCR or Legion.
• NCR — At the beginning of your end step, return target creature card with mana value 3 or less from your graveyard to the battlefield with a finality counter on it.
• Legion — Whenever a creature you control dies, put two +1/+1 counters on target creature you control.

Temple of Malice

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {R}.

Horn of the Mark

Whenever two or more creatures you control attack a player, look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Caesar, Legion's Emperor

Whenever you attack, you may sacrifice another creature. When you do, choose two —
• Create two 1/1 red and white Soldier creature tokens with haste that are tapped and attacking.
• You draw a card and you lose 1 life.
• Caesar deals damage equal to the number of creature tokens you control to target opponent.

Boros Signet

Luxior, Giada's Gift

Equipped creature gets +1/+1 for each counter on it.
Equipped permanent isn't a planeswalker and is a creature in addition to its other types. (Loyalty abilities can still be activated.)
Equip planeswalker {1}
Equip {3}

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Elspeth Tirel

+2: You gain 1 life for each creature you control.
−2: Create three 1/1 white Soldier creature tokens.
−5: Destroy all other permanents except for lands and tokens.

Evolving Wilds

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

Exotic Orchard

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

Secure the Wastes

Create X 1/1 white Warrior creature tokens.

Paladin Elizabeth Taggerdy

Battalion — Whenever Paladin Elizabeth Taggerdy and at least two other creatures attack, draw a card, then you may put a creature card with mana value X or less from your hand onto the battlefield tapped and attacking, where X is Paladin Elizabeth Taggerdy's power.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Plains

Corpse Knight

Whenever another creature you control enters, each opponent loses 1 life.

Blood Crypt

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

Denethor, Ruling Steward

At the beginning of your end step, if a creature died under your control this turn, create a 1/1 white Human Soldier creature token.
{2}, Sacrifice another creature: Each opponent loses 1 life and you gain 1 life.

Temple of Civilization

(Transforms from Ojer Taq, Deepest Foundation.)
{T}: Add {W}.
{2}{W}, {T}: Transform this land. Activate only if you attacked with three or more creatures this turn and only as a sorcery.

Ojer Taq, Deepest Foundation

Vigilance
If one or more creature tokens would be created under your control, three times that many of those tokens are created instead.
When Ojer Taq dies, return it to the battlefield tapped and transformed under its owner's control.

Ojer Taq, Deepest Foundation // Temple of Civilization

Krenko, Tin Street Kingpin

Whenever Krenko attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

Blood Aspirant

Whenever you sacrifice a permanent, put a +1/+1 counter on this creature.
{1}{R}, {T}, Sacrifice a creature or enchantment: This creature deals 1 damage to target creature. That creature can't block this turn.

Keeper of the Accord

At the beginning of each opponent's end step, if that player controls more creatures than you, create a 1/1 white Soldier creature token.
At the beginning of each opponent's end step, if that player controls more lands than you, you may search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Zagras, Thief of Heartbeats

This spell costs {1} less to cast for each creature in your party.
Flying, deathtouch, haste
Other creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a planeswalker, destroy that planeswalker.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Bedevil

Destroy target artifact, creature, or planeswalker.

Forsaken Sanctuary

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

Bastion of Remembrance

When this enchantment enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Luxury Suite

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

Talisman of Conviction

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

Lae'zel, Vlaakith's Champion

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.
Choose a Background (You can have a Background as a second commander.)

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.

Mirkwood Bats

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

Shatter

Godless Shrine

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

Tajic, Legion's Edge

Haste
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Prevent all noncombat damage that would be dealt to other creatures you control.
{R}{W}: Tajic gains first strike until end of turn.

Go for the Throat

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Ascend from Avernus

Return all creature and planeswalker cards with mana value X or less from your graveyard to the battlefield. Exile Ascend from Avernus.

Lash of the Balrog

As an additional cost to cast this spell, sacrifice a creature or pay {4}.
Destroy target creature.

Elspeth, Knight-Errant

+1: Create a 1/1 white Soldier creature token.
+1: Target creature gets +3/+3 and gains flying until end of turn.
−8: You get an emblem with "Artifacts, creatures, enchantments, and lands you control have indestructible."

Mortify

Craig Boone, Novac Guard

Reach, lifelink
One for My Baby — Whenever you attack with two or more creatures, put two quest counters on Craig Boone. When you do, Craig Boone deals damage equal to the number of quest counters on it to up to one target creature unless that creature's controller has Craig Boone deal that much damage to them.

Army of the Damned

Create thirteen tapped 2/2 black Zombie creature tokens.
Flashback {7}{B}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Dragonskull Summit

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

Skullclamp

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

Sol Ring

Nomad Outpost

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

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Orzhov Signet

Loyal Apprentice

Haste
Lieutenant — At the beginning of combat on your turn, if you control your commander, create a 1/1 colorless Thopter artifact creature token with flying. That token gains haste until end of turn.

Swamp

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.