Burakos, Party Leader

Once the game begins, your two commanders are tracked separately. If you cast one, you won't have to pay an additional {2} the first time you cast the other. A player loses the game after having been dealt 21 combat damage from any one of them, not from both of them combined (although your Background won't usually be a creature anyway).

If your Commander deck has two commanders, you can include only cards whose own color identities are also found in your commanders' combined color identities.

If you control a Background that grants an ability to commander creatures you own, and you own more than one commander creature, each of them will have that ability.