Board Thread:Naruto Discussions/@comment-3568954-20140523074558/@comment-24022934-20140710081400

We don't know how exactly a Senju would awaken his own Rinnegan, because Uchiha basically lack of the "Sage's body" so that's why they need a piece of Senju DNA. And both Sasuke and Naruto have transcended from Indra and Asura, because even though they were powerful, they didn't have either the Rinnegan or the Six Paths Sage Technique. Even Kaguya compares the duo with Hagoromo and Hamura rather than Indra and Asura.