TOBI can possibly be kagami (theory)
LET ME PUT MY FLAME PROOF JACKET ON , i made this thread becuz i belive that tobi is kagami, kagami time space ninjutsu has been said to be similar to the 2nd hokage, Tobirama's jutsu and kagami was in the same team as him so it is possible he somehow learned it and perfected it.
Tobi might be UCHIHA KAGAMI.. who might be the son of madara and probably possesses his eye(s). He has been shown to have similar hair as shisui which may have led him to hold a grudge against danzo and co. and probably the reason why he got angry when kabuto talked about reviving him through his eye. We know that kagami and danzo had similar goals/interests so its possible that this is the reason why the blood mist village while under the control of tobi and root under the control of danzo had similar practices.
Tobi constantly refers to himself in the third person just as he did with kakashi,yamato and naruto just before the kage summit which means he seems determined that people know this, as if trying to decieve them into thinking and fearing the fact that he is madara. While madara was fabled to hold the Eternal Mangakyou Sharingan, Tobi has failed to even show us a mangakyou sharingan. He has not used ameterasu once as has been said that madara was one of the first use it.
This leads me to a theory. We all know that Kagami Uchiha was amoungst the ranks of the past and present powers of konoha. Who is to say he kept on good terms?
Check this, Tobi was said to have helped Itachi with the massacre for the greater good of konoha but Madara would've never agreed to such a thing, with the pride of his clan in his heart, who would? Kagami was friends with someone thought to conspire against the uchiha, he would've been an outcast amoungst the uchiha and whilst this is happening his team might have his back but the other villagers would grow suspicious.
As years go on He begins to start a family with a woman and bear a child named "Shi Sui" (as some people have noticed the resemblance). As years go on so do relations age. The elders made the decision to kill off the uchiha and danzou and Itachi Obliged. Danzou kills Kagami's and took his eye. The elders had all decided to kill off the uchiha regardless of there ties with kagami and kagami decided to go on the war path not against konoha but his heartless friends by using the one weapon to which they didn't expect, an uchiha surviver. He uses the name "Tobi" as an antagonisation to his former friends, a play on the name "Tobirama" his former teacher who he had trusted as his friend and mentor and who would have saved his clan and the village at the same time. i save the ther best for last, more details later, your thoughts