I believe Tobi is Izuna because he say's to Konan that the Rinnegan in Nagato's eye sockets were his to begin with. When Madara is reborn, he say's, "That brat finally managed to grow, huh?" And then, later on in the battle, he activates the Rinnegan which he unlocked after battling Hashirama Senju.
Madara's eyes are implants. They belong to Izuna. Those who say that Izuna died, there is such stuff as revival in Naruto.
Madara's eyes are implants. They belong to Izuna. Those who say that Izuna died, there is such stuff as revival in Naruto.