Board Thread:Naruto Discussions/@comment-24120130-20140607191120/@comment-12002719-20140608223637

Perhaps the Shinju's eye is the true version of the Rinnegan. Not that Madara and Hagoromo's Rinnegan is a copy or something like that but more akin to how the Sharingan works with it maturing, but nothing really like that at all. What I'm thinking is that Kaguya and Madara's third eye only manifests itself when the Shinju's chakra is present. Its chakra awakens this specific, original, final, whatever, form of the Rinnegan. Hagoromo didn't possess the Shinju's actual chakra and so possessed his version of the Rinnegan, one which could be replicated by possessing his chakra, namely by uniting Senju and Uchiha DNA inside on person. I don't really know how Sasuke's Rinnegan fits into this or why Obito didn't awaken a third eye either but I'll chalk it up to magic at this point. To me, this seems like a logical explanation but its only a theory. Don't give me flak if you don't agree with it, please.