The truth is Naruto has the whole nature on his side. People still think Kabuto was wrong when he said he was the closest thing to Rikudo. However, it has been proven by Madara and Obito. The power of Rikudo is not Rinnegan. Rather, it is the Senjutsu of the six paths. As soon as Obito and Madara obtained the Senjutsu of the six paths, they declared that they have attain the power of Rikudo.
Now, the Sasuke fapboy can rejoyce because Naruto is not willing to destroy Sasuke. Otherwise, Sasuke would be killed from the start of the fight. Remember when Naruto pumped natural energy; Sasuke said he is getting serious. This alone prove that Naruto is not even serious yet about hurting Sasuke, but just preparing to counter Sasuke's biju power with subsequent amount of sage chakra.
The truth is, if Naruto wanted, he could just fight Sasuke with clones. Thus, he does not need to have power up. Also, folks, remember edo Madara and edo Hashirama.
Edo Madara: Has Hashirama's power + His own EMS + Rinnegan.
Edo Hashirama: He was just diluted Hashirama.
Yet, Edo hashirama even trapped Madara with wooden dragon and gates before Naruto hit him. The truth is that trying to be what you are not naturally never work - saith Itachi!