looking back at chapter 486 tobi doesn't look very old, at least not from the sides. in chapter 509 tobi says don't underestimate uchiha eyes, does this mean he's not uchiha? but in 509 it says tobi was the one who gave nagoto the rinnegan? does he mean he himself or him as in the real madarra? and how's that possible seeing how nagoto had that flashback of how he awakened the rinnegan. and in 510 tobi used izanagi but doesn't that mean he also has some of the senju power? i presume he took the first hokage cells a different way since he says in chapter 510 about how some have made an incomplete izanagi, unable to control hashirama's power completely (danzo). i have to say it was a good plot twist making us think at least that tobi wasn't madarra but i don't think the author planned it very well with all the times tobi calls himself madarra and up until now i'd just thought when he said wanted to become complete that that had meant mardarra was broken and needed to rejuvenate. it seems like madarra younger brother is dead, seeing how we saw the dead body in tobi's (madarra) flashback with sasuke. and obito wouldn't make a good tobi because obito is kakashi's inspiration and making him the bad guy would ruin that.