Even if Sasuke dosn't turn good, and Naruto and him fight to the death, I think that would come before Madaras final defeat, only because that way Naruto could then have the will to kill Madara that won't let him lose(kind of like bleach, lol). He'd go out for revenge. Plus, after Madara, there really isn't anyone stronger. If there was, Kishi would be pulling a DBZ, and that would be stupid.

Besides, just think about it. Even if Oro came back via Kabuto after Madara's been taken care of, if Naruto was able to take down Madara(even if it was a joint effort with others), I really don't see how Oro would pose a threat.

About the Kyuubi thing, the Kyuubi will always be there, so long as Naruto is, so I don't really see him as counting as even the same kind of antagonist as the others listed. There's a few things that could happen:

-Naruto Dies, so does the Kyuubi.

-Naruto could get to the point where he can completly control the Kyuubi, like Bee is able to, and that kind of eliminates him as being an 'antagonist'.

I know I said before that I think that the Sasuke thing will be delt with before the big, final elimination of Madara, but I'm still back and forth on this. IMO, I think it's more likly, but there is that chance that Sasuke vs. Naruto could be the final thing Kishi wants to adress. If it dose turn out this way, I think the only thing that could be done would be Either one or both of them dies. Because, IMO, if Sasuke was still 'evil' after all the time that would have passed, and everything he was bound to have found out at that point, there realistically would be no hope for him to change his mind. That would be it.

after he is done taking over kabuto