Anyway was just thinking, that, what IF, what IF, Madara learned of the Mind Transfer technique that Ino's clan uses, and took over someone and played as Madara while using their body.
Then as that body was decaying and/or Madara wanted a new one, he used the technique to transfer to Obito's body, well don't know why but used it because of the sharingan. Healed Obito up and used his body as his vessel.
Might explain some time lapse or things that could be messed up with the manga as how Madara lived so long, how Obito/Tobi knows vast knowledge, things like that.
Just guessing, no reason for Obito to go crazy and start up a criminal organization. Next chapter should probably reveal why Tobi/Obito is evil.