But for extra trickiness: all of the permanents don’t need to be controlled by one player. If your opponent has a few Invisible Stalkers staring you down (or maybe one with 5 or 15 +1/+1 counters on it), and you have an Invisible Stalker of your own, you can aim a Detention Sphere at your own Stalker to exile his as well! The reason for that is that Sphere says to exile ALL nonland permanents that share a name with the target, not just ones controlled by the controller of the original target.
Today’s Rules Tip written by Trevor Nuñez