Madara's Survival (Theory0
Two pages in Chapter 626 really stood out to me as to how Madara survived.
On this page at the end you can clearly see that Madara has his EMS activated.
On the start of the next page what is the first panel shown?
A moon, a coincidence? I think not. It coincides with his current Moon's eye Plan. and may be Madara's genjutsu....Yet later on in the page you can see that Madara's EMS is not activated, maybe to make Hashi believe his Wood clone was going to work?
In my opinion Madara used Tsukiyomi on Hashirama to make him believe he killed Madara, during which time Madara got the Senju DNA required to fulfill the other interpretation on this page.
This would most likely have to do with both Senju and Uchiha DNA, being required to unlock the Rinnegan.
He wanted the Rinnegan to further read the stone tablet and like the Eldest son, use that power to bring this world into "peace," through his moons eye plan.
This is just a theory, let me know what ya think, dont hate on me too much xD.