Board Thread:Naruto Discussions/@comment-28450860-20160622145346/@comment-25122992-20160622212228

Yeah, Nagato was using the Rinnegan efficiently, but not masterfully. It's very simple - Asura's reincarnates just aren't specialised on doujutsu prowess, unlike those of Indra, so with this logic, even if Asura's reincarnate is going to awaken the Rinnegan, it's technically not the power they are most familiar with, thus he still wouldn't be able to bring forth the same Rinnegan's potential as Indra's reincarnate in his place. Overall, Rinnegan is "eyes" evolution, which is actually Indra's field of speciality, and although this power is beyond his natural limits, it's still natural for his reincarnates to have a better compatibility with it, since they have the affinity and the most suitable skills for handling a doujutsu.