I've always wondered how Edo Madara will be defeated...he's pretty much invincible in his current form. Some people think that Obito will betray him. Sure, it might happen, but Madara is obviously prepared for that (judging by his smirk on 614). For Naruto to defeat Madara, he has to be alive, as Naruto can't seal him. For that reason, Madara will have to be revived. Is there any other way of defeating him?