Personally i think there is a possibility that Tobi a clone of Madara made out of White Zetsu material da Madara himself as Madara knows of Tobi's existence. That can also explain why Tobi seems to share many of Madara's traits ( of course he might be acting, but here i'm assuming that those are actual ) and since Madara himself obtained the Rineegan before his death, it is probably those eyes that Tobi claims to have dato Nagato. ( Madara knows about Nagato as well) This is only my theory and if there is any commenti please tell me.^^
