This theory would explain where Madara and Sasuke would fit.Plus.. If madara(tobi) is in the history.. how Sasuke will fit in? Sure its manga for Naruto, but Kishimoto wouldn't just use Sasuke to kill his brother and thats it..
^This is the second theory that I'd like to see in the outcome of the manga.
At least there's a couple decent theory to read among the 95% of the total crappy theories in the NF forum. Since the Tengu thing is a theory, it's meant not to be perfect or else it's no longer a theory.