Board Thread:Theories and Speculation/@comment-35023081-20190918151946/@comment-38812954-20190918153434

The rinnegan is actually the true dojutsu of Ashura and his reincarnates. Madara needed hashirama, to even awaken the rinnegan (in both his eyes to). With his mangekyou not just going straight to the rinnegan like Hagoromo (because he was literally the embodiment of the two halves of power. With his yang power instantaneously enhancing his yin power). If hashirama just took Madara's eyes or DNA, he would awaken the rinnegan. Without even being born with sharingan and in both his eyes to. Because he has the vital physical vitality for it (to handle two rinnegan).

The rinnegan essentially is what I like to call the enlightened eyes.