Legion Loyalty

Creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Battle Angels of Tyr

Flying, myriad
Whenever this creature deals combat damage to a player, draw a card if that player has more cards in hand than each other player. Then you create a Treasure token if that player controls more lands than each other player. Then you gain 3 life if that player has more life than each other player.

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.)

Kaldra Compleat

Living weapon
Indestructible
Equipped creature gets +5/+5 and has first strike, trample, indestructible, haste, and "Whenever this creature deals combat damage to a creature, exile that creature."
Equip {7}

Lightning Greaves

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

Cori Mountain Monastery

This land enters tapped unless you control a Plains or an Island.
{T}: Add {R}.
{3}{R}, {T}: Exile the top card of your library. Until the end of your next turn, you may play that card.

The Master, Multiplied

Myriad
The "legend rule" doesn't apply to creature tokens you control.
Triggered abilities you control can't cause you to sacrifice or exile creature tokens you control.

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Dalek Squadron

Menace
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

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.)

Neriv, Heart of the Storm

Flying
If a creature you control that entered this turn would deal damage, it deals twice that much damage instead.

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.

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Great Arashin City

This land enters tapped unless you control a Forest or a Plains.
{T}: Add {B}.
{1}{B}, {T}, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token.

Dalkovan Encampment

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {W}.
{2}{W}, {T}: Whenever you attack this turn, create two 1/1 red Warrior creature tokens that are tapped and attacking. Sacrifice them at the beginning of the next end step.

Lavaspur Boots

Equipped creature gets +1/+0 and has haste and ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {1}

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Rising of the Day

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

Arcane Signet

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

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.

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter tapped.

Commander's Sphere

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

Sol Ring

Anger

Haste
As long as this card is in your graveyard and you control a Mountain, creatures you control have haste.

Goro-Goro, Disciple of Ryusei

{R}: Creatures you control gain haste until end of turn.
{3}{R}{R}: Create a 5/5 red Dragon Spirit creature token with flying. Activate only if you control an attacking modified creature. (Equipment, Auras you control, and counters are modifications.)

Fervor

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

Frenzied Saddlebrute

Haste
All creatures can attack your opponents and planeswalkers your opponents control as though those creatures had haste.

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.