Keyword: Partner

Mono Eminence — If Auntie Flint is on the battlefield or in the command zone and your deck’s color identity is mono-black, creatures you control get +1/+0.
Whenever Auntie Flint attacks, another target creature gains fear until end of turn.
Partner (You can have two commanders if both have partner.)

Mono Eminence — As the game begins, if Mr. Wiggles is your commander and your deck’s color identity is monogreen, at the beginning of your first upkeep, search your library for a Forest card, put it onto the battlefield tapped, then shuffle.
Flying
Partner (You can have two commanders if both have partner.)

If Enolc is one of two partner commanders, it’s a copy of your other commander except it retains its name. (Including mana cost.)
If Enolc isn’t a commander, you may cast it as though it was a copy of any of your commanders.
Partner (You can have two commanders if both have partner.)

Whenever Armix, Filigree Thrasher 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.)

Deathtouch
Whenever Silas Renn, Seeker Adept deals combat damage to a player, choose target artifact card in your graveyard. You may cast that card this turn.
Partner (You can have two commanders if both have partner.)

+2: Until your next turn, up to two target creatures each have base power and toughness 0/3 and lose all abilities.
−2: Target player draws two cards. Until your next turn, instant, sorcery, and planeswalker spells that player casts cost less to cast.
−8: Target player gets an emblem with “Whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.”
Partner with Rowan Kenrith
Will Kenrith can be your commander.

+2: During target player’s next turn, each creature that player controls attacks if able.
−2: Rowan Kenrith deals 3 damage to each tapped creature target player controls.
−8: Target player gets an emblem with “Whenever you activate an ability that isn’t a mana ability, copy it. You may choose new targets for the copy.”
Partner with Will Kenrith
Rowan Kenrith can be your commander.

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.)

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.)

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.)

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.)

Commanders you control have menace and deathtouch.
Partner (You can have two commanders if both have partner.)

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.)

Flying
Spells your opponents cast that target one or more commanders you control cost more to cast.
Partner (You can have two commanders if both have partner.)

Lifelink
At the beginning of each of your postcombat main phases, you may pay X life, where X is the number of opponents that were dealt combat damage this turn. If you do, draw X cards.
Partner (You can have two commanders if both have partner.)

At the beginning of each player’s end step, that player may draw a card if a player other than you lost life this turn.
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.)

: Scry 1, then reveal the top card of your library. If it’s a land card, put it onto the battlefield tapped. Otherwise, draw a card.
Partner (You can have two commanders if both have partner.)

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.)

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

Flying
Whenever Siani, Eye of the Storm attacks, scry X, where X is the number of attacking creatures with flying.
Partner (You can have two commanders if both have partner.)

At the beginning of combat on your turn, creatures you control get +3/+3 and gain trample until end of turn.
: Until end of turn, target land you control becomes a 1/1 Elemental creature with vigilance, indestructible, and haste. It’s still a land.
Partner (You can have two commanders if both have partner.)

When Alharu, Solemn Ritualist enters, put a +1/+1 counter on each of up to two other target creatures.
Whenever a nontoken creature you control with a +1/+1 counter on it dies, create a 1/1 white Spirit creature token with flying.
Partner (You can have two commanders if both have partner.)

You may have Sakashima of a Thousand Faces enter 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.)