We were all led on to believe that Obito died underneath the rock that crushed him. At this point Obito was a child and weak, and he certainly should have died. My question for you is, who saved him? My guess is Orochimaru, he is the only person I can think of that would have been capable to fix is body. This is also why I think he was brought back into the story line. The only other people I can think of who might have saved him would be Zetsu or the real Madara. Madara has stated that he knows about Tobi/Obito and it seems as though Obitos body is the same as Zetsu's. I've digressed but what do you think? Who saved Obito?