Board Thread:Versus Debates/@comment-25122992-20160502134142/@comment-734582-20160502154720

Obito would win. I think it's pretty clear Madara intended to use Black Zetsu to control Obito. He thanks Naruto for weakening him, indicating that Madara didn't actually have to win the fight with Obito. He just needed just enough of an advantage for Black Zetsu to take over. And since Black Zetsu managed to control Madara in the end, it's obvious BZ would've been able to latch on to and defeat even Juubito