Trynn, Champion of Freedom

Note that the target player searches their library (which may be affected by effects such as that of Stranglehold) and that the card they find is revealed, even though these words aren't included in the ability's reminder text.

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 damage from one of them, not from both of them combined. Command Beacon's effect puts one into your hand from the command zone, not both.

Both commanders start in the command zone, and the remaining 98 cards of your deck are shuffled to become your library.

A creature with a "partner with" ability can't partner with any creature other than its designated partner. Losing a partner ability during the game doesn't cause either to cease to be your commander.

The triggered ability of the "partner with" keyword still triggers in a Commander game. If your other commander has somehow ended up in your library, you can find it. You can also target another player who might have that card in their library.

"Partner with [name]" represents two abilities. The first is a triggered ability: "When this permanent enters the battlefield, target player may search their library for a card named [name], reveal it, put it into their hand, then shuffle their library."