WARNING: The following contains spoilers for Chapter 64 of Boruto: Naruto Next Generations, “Control,” by Masashi Kishimoto, Mikio Ikemoto, Mari Morimoto and Snir Aharon, now available in English from Viz Media.
In the Naruto series, one of the most powerful tools a shinobi could have was the Sage Mode. Also known as "hermit mode", this empowered state can only be entered by mixing natural energy with one's inherent chakra, creating senjutsu chakra. Now, come the Boruto manga, Naruto has upgraded this weapon big time after losing Kurama. While it was thought his arsenal was depleted, this could power him immensely to once more become the free ninja world's biggest asset.
Sage Mode allows users to tap into the world's natural force, opening up new techniques and allowing them to enhance existing ones, something Minato (Naruto's father) also did. Most notably, though, is Jiraiya, Naruto's mentor and godfather, who became a boss at it, teaching Naruto about it with the help of the toads at Mount Myōboku.
Naruto spent quite a bit of time there, preparing to fight the Akatsuki which would allow him to become a WMD against Kaguya and her pawns, Obito and Madara Uchiha. Ironically, Orochimaru did the same at the Ryūchi Cave using the snakes there, but no one has perfected this art like Naruto and Jiraiya since Hashirama's time.
Given that Naruto had Kurama's Nine Tails Demon Fox energy as well, he surpassed the Sage of the Six Paths and even Hashirama himself, with Rasengans that could destroy cities, generate hundreds of shadow clones, then use them to transfer energy to other weak allies.
Basically, Naruto was a god, even learning how to not become tired as well -- which was a risk of Sage Mode. But once more, Naruto has reminded readers that he doesn't need Kurama as much as many believed. It's confirmed here when Naruto locks onto Boruto's signature outside the Konoha forest. He and Shikamaru's sensory team were struggling to track Kawaki's chakra as they knew Code was hunting the boys, but Naruto activates Sage Mode to find them.
Shikamaru's worried but the intrepid Seventh Hokage makes it clear: he can use this mode longer and doesn't get drained, which he believes has been from years of wisdom and using it with Kurama. Of course, no one knows how it'll actually perform without the Tailed Beast around, but Naruto is confident he can wield the power. It'll allow him to sense chakra and attacks without even being able to see them, which will help as Code can teleport in the blink of an eye and seems impervious to Boruto's Karma mark.
This upgrade also has Boruto fans giddy to see if Naruto can improve on Sage Mode with Koji Kashin (the Jiraiya clone) around. He hasn't been seen since he fought Isshiki and barely survived, so this moment could have him and Naruto training once more as the ex-Kara agent seems to be an expert in Sage Mode. Thus, it paints an enticing prospect as life changes for Naruto in the field.
