Breeches, Brazen Plunderer

Menace
Whenever one or more Pirates you control deal damage to your opponents, exile the top card of each of those opponents' libraries. You may play those cards this turn, and you may spend mana as though it were mana of any color to cast those spells.
Partner (You can have two commanders if both have partner.)

Adun Oakenshield

{B}{R}{G}, {T}: Return target creature card from your graveyard to your hand.

Bill the Pony

When Bill the Pony enters, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Sacrifice a Food: Until end of turn, target creature you control assigns combat damage equal to its toughness rather than its power.

Adriana, Captain of the Guard

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other creatures you control have melee. (If a creature has multiple instances of melee, each triggers separately.)

Éomer, King of Rohan

Double strike
Éomer enters with a +1/+1 counter on it for each other Human you control.
When Éomer enters, target player becomes the monarch. Éomer deals damage equal to its power to any target.

Hakka, Whispering Raven

Flying
Whenever Hakka deals combat damage to a player, return it to its owner's hand, then scry 2.

Alrund, God of the Cosmos

Alrund gets +1/+1 for each card in your hand and each foretold card you own in exile.
At the beginning of your end step, choose a card type, then reveal the top two cards of your library. Put all cards of the chosen type revealed this way into your hand and the rest on the bottom of your library in any order.

Alrund, God of the Cosmos // Hakka, Whispering Raven

Aryel, Knight of Windgrace

Vigilance
{2}{W}, {T}: Create a 2/2 white Knight creature token with vigilance.
{B}, {T}, Tap X untapped Knights you control: Destroy target creature with power X or less.

Don Andres, the Renegade

Each creature you control but don't own gets +2/+2, has menace and deathtouch, and is a Pirate in addition to its other types.
Whenever you cast a noncreature spell you don't own, create two tapped Treasure tokens.

Ardoz, Cobbler of War

Haste
Whenever Ardoz or another creature you control enters, that creature gets +2/+0 until end of turn.
{3}{R}: Create a 1/1 red Goblin creature token with haste. Activate only as a sorcery.

Arthur, Marigold Knight

Haste
Whenever Arthur and at least one other creature attack, look at the top six cards of your library. You may put a creature card from among them onto the battlefield tapped and attacking. Put the rest on the bottom of your library in a random order. Return that creature to its owner's hand at end of combat.

Éomer of the Riddermark

Haste
Whenever Éomer attacks, if you control a creature with the greatest power among creatures on the battlefield, create a 1/1 white Human Soldier creature token.

Alesha, Who Smiles at Death

First strike
Whenever Alesha attacks, you may pay {W/B}{W/B}. If you do, return target creature card with power 2 or less from your graveyard to the battlefield tapped and attacking.

Armix, Filigree Thrasher

Whenever Armix attacks, you may discard a card. When you do, target creature defending player controls gets -X/-X until end of turn, where X is the number of artifacts you control plus the number of artifact cards in your graveyard.
Partner (You can have two commanders if both have partner.)

Avacyn, the Purifier

Flying
When this creature transforms into Avacyn, the Purifier, it deals 3 damage to each other creature and each opponent.

Archangel Avacyn

Flash
Flying, vigilance
When Archangel Avacyn enters, creatures you control gain indestructible until end of turn.
When a non-Angel creature you control dies, transform Archangel Avacyn at the beginning of the next upkeep.

Archangel Avacyn // Avacyn, the Purifier

Brothers Yamazaki

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
If there are exactly two permanents named Brothers Yamazaki on the battlefield, the "legend rule" doesn't apply to them.
Each other creature named Brothers Yamazaki gets +2/+2 and has haste.

Éomer, Marshal of Rohan

Haste
Whenever one or more other attacking legendary creatures you control die, untap all creatures you control. After this phase, there is an additional combat phase. This ability triggers only once each turn.

Agent Frank Horrigan

Trample
Agent Frank Horrigan has indestructible as long as it attacked this turn.
Whenever Agent Frank Horrigan enters or attacks, proliferate twice. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there.)

Azami, Lady of Scrolls

Tap an untapped Wizard you control: Draw a card.

Dee Kay, Finder of the Lost

When Dee Kay enters, open an Attraction.
Whenever you roll a 2, each opponent loses 1 life and you gain 1 life.
Whenever you roll a 4, you may tap or untap target artifact or creature.
Whenever you roll a 6, return target creature card from your graveyard to your hand.

Adeline, Resplendent Cathar

Vigilance
Adeline's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Captain Ripley Vance

Whenever you cast your third spell each turn, put a +1/+1 counter on Captain Ripley Vance, then it deals damage equal to its power to any target.

Charix, the Raging Isle

Spells your opponents cast that target Charix cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Emrakul, the World Anew

When you cast this spell, gain control of all creatures target player controls.
Flying, protection from spells and from permanents that were cast this turn
When Emrakul leaves the battlefield, sacrifice all creatures you control.
Madness—Pay six {C}.

Baldin, Century Herdmaster

During your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

Ben-Ben, Akki Hermit

{T}: Ben-Ben deals damage to target attacking creature equal to the number of untapped Mountains you control.

Alistair, the Brigadier

Whenever you cast a historic spell, create a 1/1 white Soldier creature token. (Artifacts, legendaries, and Sagas are historic.)
Whenever Alistair attacks, you may pay {8}. If you do, creatures you control get +X/+X until end of turn, where X is the number of historic permanents you control.

Astrid Peth

Whenever Astrid Peth enters or attacks, create a Food token.
Brand-new Sky — Whenever you sacrifice a Clue or Food, Astrid Peth explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Anya, Merciless Angel

Flying
Anya gets +3/+3 for each opponent whose life total is less than half their starting life total.
As long as an opponent's life total is less than half their starting life total, Anya has indestructible.

Bortuk Bonerattle

Domain — When Bortuk Bonerattle enters, if you cast it, choose target creature card in your graveyard. Return that card to the battlefield if its mana value is less than or equal to the number of basic land types among lands you control. Otherwise, put it into your hand.

Darien, King of Kjeldor

Whenever you're dealt damage, you may create that many 1/1 white Soldier creature tokens.