Stalking Leonin

When Stalking Leonin enters, secretly choose an opponent.
Reveal the player you chose: Exile target creature that's attacking you if it's controlled by the chosen player. Activate only once.

Murders at Karlov Manor Commander

When Stalking Leonin enters the battlefield, secretly choose an opponent.
Reveal the player you chose: Exile target creature that's attacking you if it's controlled by the chosen player. Activate only once.

The List

Commander 2021

Commander 2017

When Stalking Leonin enters the battlefield, secretly choose an opponent.
Reveal the player you chose: Exile target creature that's attacking you if it's controlled by the chosen player. Activate this ability only once.

Treasure Chest

There are several ways to secretly choose an opponent, including writing that player's name on a piece of paper that's kept with Stalking Leonin.

If Stalking Leonin leaves the battlefield and returns, it's considered a new object. You may choose a new opponent and you may activate its last ability again.

If a creature is attacking a planeswalker you control, it's not attacking you. Stalking Leonin's last ability can't target it.

If you didn't choose an opponent when Stalking Leonin entered the battlefield, you can't pay the cost to activate its last ability. This will usually happen because you gained control of another player's Stalking Leonin or because a creature already on the battlefield became a copy of Stalking Leonin.

If you have multiple Stalking Leonins, you may choose a different opponent for each one. Be careful to keep track of which opponent is chosen for each Stalking Leonin.