Someone just posted the same theory in a seperate thread.Reading bak from the manga about Tobi/Madra. I just came with a pretty wierd yet very plausible prediction:
It is possible that tobi/madra Donot Exist Physically. Here are the facts to support this prediction:
1- Itachi Said that Madra was a shell of his former self.
2- We have not seen madra actually use any jutsu in any battle.
3- Everything passes through Madra- Almost as if he didnt exist.
4- Madra said he wanted Nagato to use his reincarnation Jutsu for him. ( & now Nagato had betrayed him)
All these facts support that Madra, is infact u may call a living spirit( with a few extra abilities). & he needs saske (or previously needed Nagato) to SYnc with the Statue(gedo mazo) to somehow Restore Him to his former State!!!!!!!
Any Comments/ additions / criticism of this prediction is welcome and appreciated!!!!
1) That's probarly just an expression meaning that he is way weaker than he used to be, I find it a bit far-fetched to say that this expression is proof that he wouldn't have a physical form.
2) yes, we haven't seen him use one, but he never had too. The only time he ever was in a battle was when he tried to hold of Naruto & co during the battle of Sasuke and Itachi. He just wanted to hold them of, if he wanted to kill them, he probarly would have used a jutsu.
3) He blocked Suigetsu's sword, so he is physical.
4) We don't know enough about this to make conclusions. If he just wanted to be resurrected, then why didn't he do it a long time ago. Nagato could revive an entire village after a long battle, it shouldn't have been that hard to revive one person when he's at full strength.