I feel like the fourth Hokage, Madara will just find a way around Kamui after seeing it a couple of times. Obito would have to end the fight really really fast. I Think Sage Kabuto could give them a run for they money.
MadaraObito vs Madara, who will win the way they're now, except that madara wouldn't be an edo, so he has limited chakrA, and don't start complaining wrong section, cause only people with no brains post it in the vs-section.