If a commander is exiled due to an effect that says "*first card name* is exiled until *second card name* leaves the battlefield" does the commander stay exiled or can it go into the command zone to be cast again?
Please use card tags. I will assume you are talking about something like Banisher Priest.
When the Commander is exiled, the owner can choose to let it go to exile or to put it into the Command Zone. If they let it go to Exile it will return when the Priest leaves the battlefield. If they put it into the Command Zone, it will still return to the battlefield as long as it has not moved from the Command Zone since then. It if it cast and put back into the Command Zone before Priest leaves, the Priest will not return it.
Note this is different than something like Oblivion Ring because O Ring has a second trigger to bring back the "exiled card". Since the Commander is not in Exile (assuming they put it into the Command Zone) it won't return anything.
Also, this should be in the normal Rulings Forum as this forum is more about the meta rules specific to Commander (such as Deck Construction questions).
When the Commander is exiled, the owner can choose to let it go to exile or to put it into the Command Zone. If they let it go to Exile it will return when the Priest leaves the battlefield. If they put it into the Command Zone, it will still return to the battlefield as long as it has not moved from the Command Zone since then. It if it cast and put back into the Command Zone before Priest leaves, the Priest will not return it.
Note this is different than something like Oblivion Ring because O Ring has a second trigger to bring back the "exiled card". Since the Commander is not in Exile (assuming they put it into the Command Zone) it won't return anything.
Also, this should be in the normal Rulings Forum as this forum is more about the meta rules specific to Commander (such as Deck Construction questions).