I seriously just love the hell out of your posts, man. all of em are pretty legit. One of my favorite basers. And I don't mean that you're a crackhead...eh... forget it.
Maybe he doesn't have a mouth? He was born without it, so chakra keeps on leaking out so he puts a mask on.
Or maybe it doesn't matter who's underneath the mask. it could be anybody. It's his actions that define him. Haha like batman
maybe when he takes that mask off orochimaru(who was hiding inside kakashi many years just to get his sharingan) will jump out of his mouth and fodderize madara xd