Board Thread:Naruto Discussions/@comment-1512913-20170417105433/@comment-3568954-20170420084454

the power of the sharingan isn't actually really housed in the eye but the brain of the uchiha. its true the eyes have some of said chakra but an uchiha would none the less till have access to the sharingan chakra in their brain even without eyes. so in theory a blind uchiha could just still someone elses eyes and then send sharingan chakra from their brain to the new eyes and awaken the Sharingan in the new eyes.

with that being said when izuna gave his eyes to madara the EMS came about when Madara activated izuna's mangekyou along with his own mangekyou at the same time. so the EMS is the combination of the two uchiha's mangekyou when these two powers merge the eye head chakra evolves. in theory if izuna was revived and madara gave his eyes to Izuna the eyes would still contain the power of the Rinnegan in them but would izuna be able to control that power? doubt he would. even with hashirama's cells making up most of his body obito had a hard time controlling a single eye

as for all of the so in so is an asura transmigrant because they have hashirama's cells thats b.s.