I have been thinking about this theory for weeks now. I think that tobi is kagami Uchiha. I think that Madara is his father, and he learnt the secrets of how Madara got the first's DNA. I think he somehow applied this jutsu so he could taken the DNA of The 2nd, this is how he would have got his space time ninjutsu. The second part of my theory is complicated bt when you think about it, makes sense. I think that the Mangekyou Sharingan skips a genration, and only appears in brothers, so there is possibility of EMS. I think Kagami had no siblings, but eventually he had children, I believe them to be Shisui and Obitio, yes I think those two are brothers! why would kishi show us Shisui had Mangekyou, or give it to kakashi? It's not random, there has to be some sort of pattern, i think that Fugaku was somehow related to Shisui, but like kagami Didn't have a brother, so some how Itachi and Sasuke ended up with the third set of mangekyou. So kagami originally planned to take Obito and Shisuia Sharingan, but for obvious reason found it Impossible ( possibly why he was so angry about danzo crushing shisuis eye). That is why he has taken such interest in sasuke, to take the eyes for his own. I'm sure there would have to be some other loophole involved to explain it all, but I just can't help but think Kagami is the master mind behind it all.
