I Noticed Something Random, and Made a Prediction About it that's Probly Wrong!
Madara's been using (up until recently) the alias of "Tobi" to disguise who he really is.
It was recently revealed that the Second Hokage's first name was "Tobirama".
So I was just thinking... this might be a little too weird to be a coincidence.
Yea, Madara might've just gotten the inspiration for his "nickname" from the Second Hokage's first name, or...
Or he could be using the Second Hokage's body as a host for his eternal conscience!!
Madara had a grudge against the Second. Not only was he the brother of the First and instrumental in the Senju's victory over the Uchiha, but he also was the one who gave the Uchiha the position of Konoha's "Police Force", which made them think that they were important to Konoha. This, in turn, led them to abandon Madara.
So, he could've killed the Second Hokage in the midst of some random battle with two large armies (no one can tell what's happening in those big battles anyway, and Madara could've been disguised), and then he could've taken the Second's body.
Also, a counter-argument to this "theory" (if you can call it that xD) is when Orochimaru battled the 3rd, and summoned the dead First and Second Hokages onto the battlefield. Those were NOT their original bodies. Orochimaru killed two of his comrades, and, through use of the jutsu, ash covered their dead bodies, taking the form of the First and Second Hokages, and calling their souls back from the Netherworld to inhabit them, although their free will was taken away when Orochimaru inserted some seal into their skulls.
Another counter-argument, also having to do with the 3rd vs. Oro fight, is when the 3rd sealed the soul of the Second Hokage into the stomach of the God of death. Madara would not need the soul of the Second to be present in order to use his body.
Yeah, like I said, this is a completely random "theory", and is most likely untrue. But the underlying point still exists: what's with the "Tobi"/"Tobirama" thing? Post your ideas!
(For the record, the word "Tobi" means nothing in Japanese. And the suffix "-rama" was nothing special. The First's first name was "Hashirama", so it was likely either a suffix of honor among the senju, or just simply a way in which Senju names ended. Either way, this means that the Second's first name was, in essence, just "Tobi".)