It might not make much sense as to how anyone can gain the power of this GPS capability, but it would be just convent as like finding out the element of the player that bends (/b who).
Another thing, maybe incorperating a clan/group/gang/club-alike-plugin, one could accompany the avatar as a team member through /rpgbending join [avatar's name]. This opens many features relevant to this concept, such as friendly fire (which would be disable by default) between alies of and the avatar('s) are sided, tp-ying each other or whole to or at without a permission request, set up a pinned task (/rpgbending annouce "Let's take a trip to Ba Sing Se") which anyone could read the recent/all events (/rpgbending read) like a newspeed. Also, it would be possible to assign a task for each individual member (reference to how each of the gaang friends had their own way or 'destiny' to stop and end 100 year on going War) (command: /rpgbending assign [member] <task>). Also, tamed mobs can also unite with the team (Nagga, Momo, Appa...).
An avatar can rename it how ever it wants and disable access for others If they happen to type in immature names. Command for that could be /rpgbending create <name> (if not specified, it automaticly gets name by the user ign followed by "Team " initial). /rpgbending add [player] adds it the group (avatar has to accept/deny the request settled if somebody else from the group invites someone).