Madara has been an enigma of sorts. First arriving as the goofy Tobi who drove Deidara insane then switching to the evil and powerful Madara. All of his trickery could have easily been spotted if he wasn't wearing his mask. The face of Madara Uchiha would be quickly recognized by anyone in the Land of Fire and likely many shinobi in other lands. So do you think we'll ever see Madara's face?