Thought about Tobi and Obito
Ok, so we've all heard the suspicions about the two. And the evidence:
-Tobi's right eye is shown with sharingan, while the left is not. Obito is missing his left eye.
-Madara should by all means be dead, since he was alive since before the sannin were even born. Obito would be of similar age and size to Kakashi, which Tobi appears to be.
Well, think about this for a second. Say that Obito magically survived the incident somehow and continued living. He could have made a new friend at some point and killed them for his mangekyo sharingan. That would also explain where Kakashi got his from, as everyone he knew and loved was dead prior to the timeskip. The death of a loved one is supposed to be a requirement for MS, right? It was Obito's eye that Kakashi has, so maybe his mangekyo eye somehow activated when Obito awakened MS with his remaining eye. It could also be that Rin's death triggered the awakening of MS within Obito, which then triggered it within Kakashi.
My next point, has anyone actually seen the current Madara showing off his Eternal Mangekyo? Because it's possible that he doesn't have it. I mean, I haven't seem him reveal anything more than Sharingan. We've seen flashback pictures of Madara with EMS, but never Tobi. Obito never encountered any other Uchiha, which stopped him from getting EMS.
Finally, consider Tobi's MS technique. A space time jutsu that allows him to essentially disappear at will. Sound similar to anything? Yeah, Kakashi's technique. So think of it this way. Since Obito and Kakashi are each using one of the same pair of sharingan eyes, they are both using the same MS tecnique. Obito (Tobi) simply has a way more advanced version of Kamui than Kakashi. Whereas Kakashi just focuses his eye on objects and sends them out into the middle of nowhere, Obito can concentrate Kamui onto himself to make himself essentially not exist in a certain location. Kakashi uses it purely for offense, but Obito can use it as a defense.
As for his reasons for acting as Madara Uchiha... perhaps his body is possessed? The same way Orochimaru reincarnated every 3 years, it's possible that Madara's form of immortaility is to take control of other's bodies. It explains why Obito would look like the Mizukage to Kisame, if Madara is the Mizukage and has been using Obito's body.
Well, those are my thoughts. What do you all think?