Naruto Chapter 599

[Sidnne]

Some serious now: I was looking back over the past threads a little bit, and stumbled upon a post I had made wondering if there was any significance to the thing on Madara's back the first time we saw an image of him. Turns out, that thing on his back is the weird fan weapon thing that Obito has been fighting with.

Madara: http://www.mangapanda.com/93-375-15/...apter-370.html
Obito: http://www.mangapanda.com/naruto/599/15

This leads me to believe that Obito must have really met Madara at some point.

Somehow Orochimaru ties into all of this, which is why he was brought back. I'm going to say that Obito phased into Oro's hideout, and stumbled upon his experiments with resurrection and the first's DNA. Then maybe he, with Oro's help, resurrected Madara temporarily, using the first's DNA. The edo tensei was incomplete at that time, so Madara was very weak and not able to use his powers, but Obito was able to learn a bunch of stuff from him. Somewhere in that time they created the Zetsu clones, met Nagato, and started Akatsuki. Then, since the edo tensei was incomplete, it "wore off" and Madara faded away.

This could explain how Madara knew about the "other Madara" and Nagato.