Okay, it's been a while since I posted, but I still have questions about good and evil in the Bleach universe, especially now that we have good hollows-Nell and her friends. Also there seem to be non-human hollows. I wasn't sure why this happened, but then I remembered that any living thing that gets devoured by a hollow also becomes a hollow, so I guess that explains the animal hollows, but I'm still not sure about Nell. If she can be a good girl in spite of being a hollow, and her friends can be equally harmless, why couldn't Orohime's brother Sora have become a good hollow? Does it have anything to do with being Arrancar?
And another thing, how come when Grimmjow releases his Zanpakto, his jawline mask fragment disappears? If his released form doesn't have that part, he shouldn't have it at all, I thought the mask fragments on Arrencar are supposed to be smaller parts of the larger masks they wear in full hollow form, but Grimmjow blew that out of the water, what gives?