Angelic Benediction

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, you may tap target creature.

Goblin Champion

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

Sigil of Valor

Whenever equipped creature attacks alone, it gets +1/+1 until end of turn for each other creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Altar of the Goyf

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of card types among cards in all graveyards.
Lhurgoyf creatures you control have trample.

Amber Gristle O'Maul

Haste
Whenever Amber Gristle O'Maul attacks, you may discard your hand. If you do, draw a card for each player being attacked.
Choose a Background (You can have a Background as a second commander.)

Duskmantle Prowler

Haste (This creature can attack and {T} as soon as it comes under your control.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Drana, the Last Bloodchief

Flying
Whenever Drana, the Last Bloodchief attacks, defending player chooses a nonlegendary creature card in your graveyard. You return that card to the battlefield with an additional +1/+1 counter on it. The creature is a Vampire in addition to its other types.

Imperial Subduer

Whenever a Samurai or Warrior you control attacks alone, tap target creature you don't control.

Sublime Archangel

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Other creatures you control have exalted. (If a creature has multiple instances of exalted, each triggers separately.)

Colossal Plow

Whenever Colossal Plow attacks, add {W}{W}{W} and you gain 3 life. Until end of turn, you don't lose this mana as steps and phases end.
Crew 6 (Tap any number of creatures you control with total power 6 or more: This Vehicle becomes an artifact creature until end of turn.)

Emberwilde Captain

When Emberwilde Captain enters, you become the monarch.
Whenever an opponent attacks you while you're the monarch, Emberwilde Captain deals damage to that player equal to the number of cards in their hand.

Argentum Armor

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip {6}

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.

Peerless Samurai

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a Samurai or Warrior you control attacks alone, the next spell you cast this turn costs {1} less to cast.

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.

Agent of the Shadow Thieves

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, put a +1/+1 counter on this creature. It gains deathtouch and indestructible until end of turn."

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.

Delver's Torch

Equipped creature gets +1/+1.
Whenever equipped creature attacks, venture into the dungeon. (Enter the first room or advance to the next room.)
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Reaper's Talisman

Whenever equipped creature attacks, it gains deathtouch until end of turn.
Whenever equipped creature attacks alone, defending player loses 2 life and you gain 2 life.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Ironsoul Enforcer

Whenever Ironsoul Enforcer or a commander you control attacks alone, return target artifact card from your graveyard to the battlefield.

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.

Guardians of Akrasa

Defender (This creature can't attack.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Norika Yamazaki, the Poet

Vigilance
Whenever a Samurai or Warrior you control attacks alone, you may cast target enchantment card from your graveyard this turn.

Servant of Nefarox

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

Angelic Exaltation

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of creatures you control.

Knight of Glory

Protection from black (This creature can't be blocked, targeted, dealt damage, or enchanted by anything black.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Akki Ronin

Whenever a Samurai or Warrior you control attacks alone, you may discard a card. If you do, draw a card.

Duty-Bound Dead

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{3}{B}: Regenerate Duty-Bound Dead. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Knight of Infamy

Protection from white (This creature can't be blocked, targeted, dealt damage, or enchanted by anything white.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Tempered in Solitude

Whenever a creature you control attacks alone, exile the top card of your library. You may play that card this turn.

Guild Artisan

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, you create two Treasure tokens." (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Ardent Dustspeaker

Whenever Ardent Dustspeaker attacks, you may put an instant or sorcery card from your graveyard on the bottom of your library. If you do, exile the top two cards of your library. You may play those cards this turn.

Asari Captain

Haste
Whenever a Samurai or Warrior you control attacks alone, it gets +1/+0 until end of turn for each Samurai or Warrior you control.

Aerial Surveyor

Flying
Whenever Aerial Surveyor attacks, if defending player controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.
Crew 2

Nefarox, Overlord of Grixis

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever Nefarox, Overlord of Grixis attacks alone, defending player sacrifices a creature of their choice.

Flaming Fist

Commander creatures you own have "Whenever this creature attacks, it gains double strike until end of turn."

Akrasan Squire

Eiganjo Exemplar

Whenever a Samurai or Warrior you control attacks alone, it gets +1/+1 until end of turn.

Aven Squire

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

Selfless Samurai

Whenever a Samurai or Warrior you control attacks alone, it gains lifelink until end of turn.
Sacrifice Selfless Samurai: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Sigiled Paladin

First strike
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)