A Party ability affects you normally and can also be shared with other characters. You may give the ability to any number of characters any time except during content or combat and the benefit applies whenever they are within sight of you. Characters may only benefit from one Party ability at a time, regardless of how many you or other characters have, though you may grant different abilities to different characters at the same time. You may revoke a Party ability at any time if you so choose.
If the ability is granted by a sanctum, residents of the sanctum may choose it as their Party ability, but remain limited to one Party ability at a time. The owner of the sanctum may revoke its Party abilities, but residents need not be within sight of the sanctum or the owner to benefit from them.