That's a pretty good summary. Any character who leaves and comes back later, The BigT2000, is stored in the shadow party when he/she is gone. Otherwise her/his stats would be reset to starting.levels upon returning. Problem with that in the original programming is that there are only five spots available in the shadow party, but thirteen characters (sort of, you know what I mean), so it's impossible to save everybody's stats. Thus if you ever wanted Palom and Porom back in the party, it'd be like they were never there to begin with.