"Naruto and the Sage of the Six Paths…!!" (ナルトと六道仙人…!!, Naruto to Rikudō Sennin…!!) is chapter 671 of the original Naruto manga.
Informing the unpurturbed Naruto that his son Asura's will was reincarnated into him, Hagoromo also notes that Sasuke had inherited Indra's will as well. The Sage goes on to explain how Hashirama and Madara were the previous inheritors and explained how the latter had acquired his own power after integrating Hashirama's cells into himself inadvertently mixing Asura and Indra's chakra. Delving deeper, he tells Naruto how his mother Kaguya had wielded such power far exceeding that of any human that people came to fear her as a demon who ruled over them with twofearsomedōjutsu — something he saw happening with Madara who was attempting to attain the power of the Ten-Tails to achieve power akin to that of Kaguya and Hagoromo. Stating that for too long he had been a bystander of events, the Sage asks Naruto to stop Madara before calling forth the chakra of the nine tailed beasts which Obito had sealed into the young man. As the beasts readily awaited the fulfilment of their long-time prophecy, it is revealed that the Sage is also having the same conversation with Sasuke in his subconscious — intent on including Indra in changing the world. Calling for both young men to stretch out their hands, the Sage imparts his power to both of them. Meanwhile on the battlefield a haughty Madara boasts that the Evening Elephant was not enough to take him down while a battered Guy notes that he would have to use the Night Guy after all.