Well have anybody idea about this? Most of people say that madara use/put byakugan as his 3rd eye in 3rd hole. May be its 98% possible. But does madara really need a byakugan? I mean if he really need it then he could easily get it a long time ago. Madara easily get a byakugan when or if he need it. But what about 4th very little hole(at the middle of all three eye holes). Have u any kind of clue or idea. Or madara just use if for his nose.lol.