It's really hard to decide especially since Kamui is so haxed and nobody has shown any counters to it, the only counter other than the other Kamui is FTG and in my opinion even Minato the best FTG user can't win against Obito(any form except 16 yro), but at the same time the most powerful offensive technique that Obito has is Bakufo Ranbu which gets tanked by Susanoo, and Obito can't hit Madara in cqc as Madara is fast and can just evade him. So it's really hard to decide but if Madara can take advantage of the moment Obito materializes then he might be able to hit him in cqc and severely weaken him allowing him to use black Zetsu to stall him for sometime and then finally finishes him. In addition to that according to manga portrayal the only people who are above EMS Madara are Hashirama, Indra, Ashura, Hagoromo, Hagoromo's brother and Kaguya. The rest including Rinnegan Obito with beasts and SM Kabuto with ET and BSM Naruto and EMS Sasuke are clearly below him no matter what fanboys say. The only form Obito has that is above any Juubiless Madara is Juubito and even then Juudara is above Juubito