Honestly i dont know, or do i?
I think the whole storyline of naruto is about the ancient "circle" of hatred created from the so6p sons.
I believe the Jubbi is the creator of the world and wanted to punish humanity for it's destruction and hate.
I think that Tobi and Madara are just a continuation of 1 side and Hashirama until 4th on the other side.
I think the final Villain will be Sasuke (maybe heleped by Oro), and on the other side we have Naruto.
Remember they are still teens and not grown up yet, so we haveto see their full power and moral yet.
I want right now that this war ends Obito and Madara out of the plan aka defeated.
Naruto or Sasuke becoming the Juubis host.
Sasuke doing something really unforgivable and bad becoming the worst villain of all.
a good build up before the final scenes of this manga.
thats it.