Board Thread:Naruto Discussions/@comment-4682609-20140806081616/@comment-25228549-20140810103924

I have a theory as well. When Obito "died" the first time, when they were kids and Obito gave Kakashi his eye.

Is there a slight chance that after having it for that long in his system, it still had Obito's Uchiha cells in it?

And those cells might have moulded with his own and maybe that's why he could awaken the Mangekyo the first time after killing Rin, and awakening the Susasno'o because he has Uchiha DNA?

You have no idea how much I've thought about that.