As a note, Sion for the most part will not bring the Silver Wing with him unless/until there's a specific reason to do so. He'll mention/discuss it with the monks, but doesn't see the point in risking it until they have a lead to go on. It has kind of sentimental value to him and Ryner (despite definitely being a bit ragged and tattered) so he prefers to keep it safe until needed. :|b

Also for clarification's sake, "we figured out where Ho-Oh is now we just need to get its attention" does qualify as good reason!