Board Thread:General Discussion/@comment-31283382-20131101162239/@comment-8986886-20140720021928

Gacsam wrote: 1. Arrancar is a "transformation" that apparently any hollow can achieve through tearing off their masks, which would bring out a question - why don't all of them do?

Maybe it's not common knowledge among Hollows, or perhaps they know that which Shawlong came to realize; that if an Adhujas is damaged, it can never evolve into a Vasto Lorde, and tearing off their masks could be considered taking damage. So maybe they only tear off their mask after they've lost all hope of becoming Vasto Lorde?