Keyword: Partner

At the beginning of combat on your turn, you may pay . When you do, distribute X +1/+1 counters among any number of target Elves.
Partner (You can have two commanders if both have partner.)

Partner with Shabraz, the Skyshark (When this creature enters the battlefield, target player may put Shabraz into their hand from their library, then shuffle.)
Whenever you discard a card, put a +1/+1 counter on Brallin, Skyshark Rider and it deals 1 damage to each opponent.
: Target Shark gains trample until end of turn.

Whenever Miara, Thorn of the Glade or another Elf you control dies, you may pay and 1 life. If you do, draw a card.
Partner (You can have two commanders if both have partner.)

Partner with Brallin, Skyshark Rider
Flying
Whenever you draw a card, put a +1/+1 counter on Shabraz, the Skyshark and you gain 1 life.
: Target Human gains flying until end of turn.

Reyhan, Last of the Abzan enters the battlefield with three +1/+1 counters on it.
Whenever a creature you control dies or is put into the command zone, if it had one or more +1/+1 counters on it, you may put that many +1/+1 counters on target creature.
Partner (You can have two commanders if both have partner.)

, Tap X untapped artifacts you control: Look at the top X cards of your library. Put one of those cards into your hand and the rest into your graveyard.
Partner (You can have two commanders if both have partner.)

Whenever one or more cards leave your graveyard, create a tapped 2/2 black Zombie creature token.
Partner (You can have two commanders if both have partner.)

Whenever a token you control leaves the battlefield, put a +1/+1 counter on Nadier, Agent of the Duskenel.
When Nadier leaves the battlefield, create a number of 1/1 green Elf Warrior creature tokens equal to its power.
Partner (You can have two commanders if both have partner.)

Flying
Whenever one or more Pirates you control deal damage to your opponents, you create a Treasure token for each opponent dealt damage. (It’s an artifact with “, Sacrifice this artifact: Add one mana of any color.”)
Partner (You can have two commanders if both have partner.)

As an additional cost to cast this spell, you may sacrifice any number of artifacts and/or creatures. This spell costs less to cast for each permanent sacrificed this way and less to cast for each other artifact or creature you’ve sacrificed this turn.
Trample
Partner (You can have two commanders if both have partner.)

Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner’s hand. If you win the flip, copy that spell, and you may choose new targets for the copy.
Partner (You can have two commanders if both have partner.)

As long as it’s your turn, creature tokens you control get +1/+4.
: Create a 1/1 white Soldier creature token.
Partner (You can have two commanders if both have partner.)

Flying, first strike, vigilance, trample
At the beginning of each combat, until end of turn, each other creature you control gets +1/+1 if it has flying, +1/+1 if it has first strike, and so on for double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, protection, reach, trample, vigilance, and partner.
Partner

First strike
: Add an amount of equal to the greatest power among creatures you control that entered the battlefield this turn.
Partner (You can have two commanders if both have partner.)

Whenever a commander you control attacks, put a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

: Choose another target creature. Its controller may exile it with an aegis counter on it.
, : Return all exiled cards with aegis counters on them to the battlefield under their owners’ control.
Partner (You can have two commanders if both have partner.)

You may have Sakashima of a Thousand Faces enter the battlefield as a copy of another creature you control, except it has Sakashima of a Thousand Faces’s other abilities.
The “legend rule” doesn’t apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Whenever one or more cards leave your graveyard, create a tapped 2/2 black Zombie creature token.
Partner (You can have two commanders if both have partner.)

Whenever Bruse Tarl, Boorish Herder enters the battlefield or attacks, target creature you control gains double strike and lifelink until end of turn.
Partner (You can have two commanders if both have partner.)

Artifacts you control have protection from each converted mana cost among artifacts you control.
Partner (You can have two commanders if both have partner.)

Jeska, Thrice Reborn enters the battlefield with a loyalty counter on her for each time you’ve cast a commander from the command zone this game.
0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead.
−X: Jeska, Thrice Reborn deals X damage to each of up to three targets.
Jeska, Thrice Reborn can be your commander.
Partner

First strike, vigilance
Akiri, Line-Slinger gets +1/+0 for each artifact you control.
Partner (You can have two commanders if both have partner.)

At the beginning of combat on your turn, you may attach any number of Auras and Equipment you control to target permanent or player.
Partner (You can have two commanders if both have partner.)

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.)

At the beginning of combat on your turn, you may pay . When you do, distribute X +1/+1 counters among any number of target Elves.
Partner (You can have two commanders if both have partner.)