Board Thread:Theories and Speculation/@comment-29769110-20161017201027/@comment-30323490-20171010113921

@Indk21 Actually, Sasuke would've awakened the rinnegan on his own at some point, since he received Hashirama's cells from Kabuto. Madara had a small part of Hashirama, and it took him tens of years to awaken the rinnegan, but still did it. I believe Hagormo only sped up the awakening process for Sasuke.