Originally Posted by Gakure

^In the movie, b4 Lee was petrified, he let lose some hair which later become human(looking like Lee) but far less powerful. He needed his staff he sent flying during his last moments to awaken him.

The same could happen here, Madara, seeing he has lost against Hashi, created the "Tobi" and let go the hold of the Kyuubi making Hashi thought he wrestled the kyuubi from him. Sent out the "Tobi" to use the Kyuubi to "resurrect" him.

After his resurrection 'Tobi' will fail to exist and turn back into that Madara part let loose to join with the real Madara.