To have two commanders, both must have the partner ability as the game begins. Losing the ability during the game doesn't cause either to cease to be your commander.
Glacian, Powerstone Engineer
You may tap any untapped artifacts you control, including artifact creatures that haven't been under your control continuously since the beginning of your most recent turn.
If something refers to your commander while you have two commanders, it refers to one of them of your choice. If you are instructed to perform an action on your commander (e.g. put it from the command zone into your hand due to Command Beacon), you choose one of your commanders at the time the effect happens.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Magali Villeneuve
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
