The Sharingan is extreemely powerful, and infinately more dangerous in the wrong hands (as we had seen with Danzo). After the Uchiha massacre, there were dozens of Sharingan avalable, and they had to be gathered. I personally think that Tobi was a Zetzu cloan made by Madra shortly before his death to pull the strings in the shadows untill he could be resurrected. *notice that he mentioned Nagato and his Rinnegan after being resurrected via Edo Tensei.* But then he hit a snag when Nagto killed himself in order to bring back the fallen citicens of Konoha. The oregional plan was no longer possible (as stated by Tobi), so Tobi decided to take things into his own hands. He brinwashed Sasuke and fueled his anger to replace Nagato as his trump card, grew 100,000 White Zetsus, and declared the Third Shinobi World War. He reclaimed the Rinnegan and created the new Six Paths of Pain in order to rise his fighting prowess (since he is a white Zetsu cloan and a "shell" of the real Madara).
If your thinking "WHY ON GOD'S GREEN EARTH DO YOU THINK IT'S A ZETSU CLOAN!?!?!? THAT THEORY IS COMPLETE ND TOTAL CRAP!!!," well don't worry, I have my resons. When Tobi lost his arm, you could see that the inside of his body looked like Zetsu goo. When a Zetsu creates a cloan, it's a perfect replica all the way down to the chakra, but if you kill it it returns to a white Zetsu--and if you cut off an arm/leg/head, then you see the interior as Zetsu goo (just like Tobi). When I first heard the idea that Tobi's a Zetsu cloan (the thought, not the descriptive theory I created), I thought it was complete and total crap. But I put some thought into it nd it can make sense.
But no, TOBI IS NOT OBITO
but seriosliy cnt wait for next manga hope we see who tobi relly is my bets on the elder son of the so6p seems only reasonoble explanaition to me
