Board Thread:Theories and Speculation/@comment-28819877-20170515143845/@comment-734582-20170516152343

Killer723 wrote: I still cant stop thinking that Orochimaru will turn those decades into days or hours, if Kishimoto planing to make him villain again. Orochimaru's goal was something along the lines of finding out the source or truth behind Ninjutsu. With Sasuke and Naruto and the revelations of the Juubi/ Kaguya, he essentially got his answers. I doubt Orochimaru will be stirring up trouble, since he's essentially doing research sanctioned by the two most powerful people in the world now.

It would be possible for him to recreate the Rinnegan, since Kabuto found Madara's body and they ought to have some Sasuke samples + and Hashirama cells. But i doubt Naruto and Sasuke would allow that. Besides, since they could clearly sense Hagoromo's power when they had the seals, i doubt Orochimaru could create such an eye in secret without either instantly knowing about it.

CyberianGinseng wrote: Not really true. Obito gave Kakashi his kekkei genkai simply by possessing him, no flesh involved. If Obito's soul had been sealed inside of Kakashi instead, like a bijuu, you'd probably have the same effect. It's a different mechanism. In the most generic terms, you need long-term exposure to the other transmigrant's chakra in order to recreate Hagoromo's chakra. This can be done with flesh (since it creates more chakra and so the supply is refreshed) or with a soul. If Madara had sealed Hashirama inside him for long enough, that would probably also make him meet the requirement. But yes, Obito possessing Kakashi is similar to how a Jinchuriki works. It seems that if you're not being possessed for very long, the effects of extraction aren't fatal (since Obito didn't suffer massively from transferring Kurama, Kakashi didn't die when Obito left and Tsunade didn't die after Dan left. Yet Edo Tensei hosts die when the soul is extracted).

It seems that if you are exposed to someone's chakra for long enough, you become compatible with that chakra and that borrowed power becomes almost your own. This happened with Gaara (had same jutsu even after Shukaku was extracted), this happened with Nagato (Had rinnegan when resurrected with Edo Tensei). presumably this also happened with Madara (after decades, Hashirama's power became his own).