What if Shisui Uchiha had a brother.
Ok guys I know by now you are sick of the threads about Obito being Tobi, but I realized something when watching the older episodes of naruto, during the first flash backs of itatchi during the Naruto Sasuke fight. During the flash back, we see itatchi is being questioned about the suicide of Shisui Uchiha. When they speak of Shisui, they use a nick name they gave him. 'Shisui the teleporter.' What an interesting name considering Tobi teleports all over the place right? We know that itatchi had to kill him to gain his Mangekyou Sharingan. He was itatchi's best friend which is why he awakend it, However sasuke didn't have to kill itatchi to get his. He saw Itatchi die in front of him... but he didn't actually deliver the final blow, and Itatchi clearly had the upper hand, he would have killed sasuke if he wanted to but we know itatchi wanted to help sasuke awaken his power. Tobi said Itatchi had to "die in front of him." That was all. Maybe He was speaking from experiance. I think at some point in Obito's 'death' Perhaps Zetsu appeared, making him stronger, and he could have had cells from Shisui, helping Obito awaken a special mangekyou, one that allows him to teleport. With his body mangled he could have used zetsu to heal him afterwards. Then he would attack the leaf, heart broken and distraught by Rin's death. He would go under a different name, Madara Uchiha, to gain power in his name, and he would want to take over the world, using the Moon's eye plan, showing the world that the Uchiha were the strongest, and it would get rid of all the hate in the ninja world, by brain washing the entire planet in infinite tsukyomi.
Not a bad theory right? I mean we don't actually know where Zetsu was during this time, and we don't know if Shisui or Obito were related or even had brothers. That being said WE DON'T KNOW, there is nothing written in stone saying that they couldn't be brothers.