Raiyuu, Storm's Edge

First strike
Whenever a Samurai or Warrior you control attacks alone, untap it. If it's the first combat phase of the turn, there is an additional combat phase after this phase.

Clifftop Retreat

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

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

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.)

Ride Down

Destroy target blocking creature. Creatures that were blocked by that creature this combat gain trample until end of turn.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Moraug, Fury of Akoum

Each creature you control gets +1/+0 for each time it has attacked this turn.
Landfall — Whenever a land you control enters, if it's your main phase, there's an additional combat phase after this phase. At the beginning of that combat, untap all creatures you control.

Bloodthirster

Flying, trample
Whenever Bloodthirster deals combat damage to a player, untap it. After this phase, there is an additional combat phase.
Bloodthirster can't attack a player it has already attacked this turn.

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Hall of the Bandit Lord

Hall of the Bandit Lord enters tapped.
{T}, Pay 3 life: Add {C}. If that mana is spent on a creature spell, it gains haste.

Izzet Signet

Unleash Fury

Double the power of target creature until end of turn.

Blasphemous Act

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

Island

Archetype of Aggression

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

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.

Ruhan of the Fomori

At the beginning of combat on your turn, choose an opponent at random. Ruhan of the Fomori attacks that player this combat if able.

Grim Reaper's Sprint

Morbid — This spell costs {3} less to cast if a creature died this turn.
Enchant creature
When Grim Reaper's Sprint enters, untap each creature you control. If it's your main phase, there is an additional combat phase after this phase.
Enchanted creature gets +2/+2 and has haste.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Negate

Terramorphic Expanse

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

Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Command Tower

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

Sol Ring

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Evolving Wilds

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

Mountain

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Hellraiser Goblin

Creatures you control have haste and attack each combat if able.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Rising of the Day

Creatures you control have haste.
Legendary creatures you control get +1/+0.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} 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.

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Mass Hysteria

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Arena of Glory

Arena of Glory enters tapped unless you control a Mountain.
{T}: Add {R}.
{R}, {T}, Exert Arena of Glory: Add {R}{R}. If that mana is spent on a creature spell, it gains haste until end of turn. (An exerted permanent won't untap during your next untap step.)

Hindering Light

Counter target spell that targets you or a permanent you control.
Draw a card.

Meticulous Archive

({T}: Add {W} or {U}.)
Meticulous Archive enters tapped.
When Meticulous Archive enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Sejiri Glacier

Sejiri Glacier enters tapped.
{T}: Add {W}.

Sejiri Shelter

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

Sejiri Shelter // Sejiri Glacier

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Calamity Bearer

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

Plains

Assault Suit

Equipped creature gets +2/+2, has haste, can't attack you or planeswalkers you control, and can't be sacrificed.
At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it.
Equip {3}

Kediss, Emberclaw Familiar

Whenever a commander you control deals combat damage to an opponent, it deals that much damage to each other opponent.
Partner (You can have two commanders if both have partner.)

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Sweeping Cleave

Target creature you control gains double strike until end of turn. (Then exile this card. You may cast the artifact later from exile.)

Two-Handed Axe

Whenever equipped creature attacks, double its power until end of turn.
Equip {1}{R}

Two-Handed Axe // Sweeping Cleave

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.

Bedlam

Blackblade Reforged

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

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Arcane Signet

Combat Celebrant

If Combat Celebrant hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Duelist's Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

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.)

Emblem of the Warmind

Enchant creature you control
Creatures you control have haste.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Hexplate Wallbreaker

For Mirrodin! (When this Equipment enters, create a 2/2 red Rebel creature token, then attach this to it.)
Equipped creature gets +2/+2.
Whenever equipped creature attacks, if it's the first combat phase of the turn, untap each attacking creature. After this phase, there is an additional combat phase.
Equip {3}{R}

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Spell Rupture

Counter target spell unless its controller pays {X}, where X is the greatest power among creatures you control.

Counterspell

Relentless Assault

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Jeskai Ascendancy

Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn. Untap those creatures.
Whenever you cast a noncreature spell, you may draw a card. If you do, discard a card.

Fellwar Stone

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

Boros Signet

Reliquary Tower

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

Divine Reckoning

Each player chooses a creature they control. Destroy the rest.
Flashback {5}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Prisoner's Dilemma

Each opponent secretly chooses silence or snitch, then the choices are revealed. If each opponent chose silence, Prisoner's Dilemma deals 4 damage to each of them. If each opponent chose snitch, Prisoner's Dilemma deals 8 damage to each of them. Otherwise, Prisoner's Dilemma deals 12 damage to each opponent who chose silence.
Flashback {5}{R}{R}

Bloodcrusher of Khorne

Trample
Devastating Charge — Other creatures you control have trample.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Tuktuk Rubblefort

Defender, reach
Creatures you control have haste.

Slip Through Space

Devoid (This card has no color.)
Target creature can't be blocked this turn.
Draw a card.

Exotic Orchard

Tear

Destroy target enchantment.
Fuse (You may cast one or both halves of this card from your hand.)

Wear

Destroy target artifact.
Fuse (You may cast one or both halves of this card from your hand.)

Wear // Tear

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Ashling's Prerogative

As Ashling's Prerogative enters, choose odd or even. (Zero is even.)
Each creature with mana value of the chosen quality has haste.
Each creature without mana value of the chosen quality enters tapped.