Board Thread:Naruto Discussions/@comment-24898250-20140730025315/@comment-24531362-20140803033848

Actionmanrandell wrote:

You do not know that. also i must add that the sharingan was in kakaashi's body for what 20 years or something like that. so the chakra of the uchiha had to have mingled with his own chakra. no where do they ever say madara can use the susanoo with out eyes because of the uchiha chakra in his body

I do know that. An Uchiha awakens the Sharingan because intense emotion causes their brain to produce a special chakra, which mutates the optic nerve, causing the eye to become a Sharingan. This chakra stays in the brain, and is likely the reason that Uchiha of high caliber can use Sharingan techniques without eyes. A degree of this chakra is also present in the eye, which is what allows transplanted eyes to function as Sharingan and, in Kakashi's case, become Mangekyo Sharingan in synergy with the oher eye in the hands of the original owner. The Sharingan chakra in the eye, though does not leave the eye. The key here is that Kakashi had the eye-type chakra that allowed usage of the techniques, but not the brain-chakra that made the techniques his own.