Naruto Uzumaki is the Seventh Hokage of Konohagakure and one of the strongest characters in the world of Boruto. As the Jinchuriki of Kurama, Naruto was quite powerful and ranked among the strongest Hokage in the story. However, after losing the power of his Tailed Beast in the fight against Isshiki Otsutsuki, he has weakened quite a bit.
While Naruto likely won't ever be as strong as he was, that's not to say that he can't get stronger in the near future in Boruto. With multiple sources of power still accessible to him, he could end up acquiring some terrific powers that aid him in battle.
7 Lava Release Chakra Mode
Lava Release Chakra Mode is an ability that only the Jinchuriki of the Four Tails can utilize. This ability allows them to access the blazing hot powers of Son Goku's lava and coat their body in it. With its powers, the fighting capabilities of the user are raised exponentially and for Naruto, this would be a great power-up.
While Naruto has lost Kurama, he should still hold the chakra of all the other Tailed Beasts within him. In that case, he should be able to access this tremendously powerful form. While it certainly isn't as strong as his former powers, it would still aid him greatly in battle.
6 Mastering Boil Release
Just like Lava Release, Naruto also has access to Boil Release through Kokuo, the Five Tails. After having received its chakra, Naruto went on to use its powers on multiple occasions in the Fourth Great Ninja War. He was seen using Boil Release: Unrivalled Strength to counter Kaguya Otsutsuki and he even incorporated it in his Rasenshuriken during the fight.
Undoubtedly, Naruto is incredibly skilled with this technique but his mastery of Boil Release can get even better. If he trains in this art, he can learn quite a few other Boil Release techniques and get even stronger. Once again, this would grant him a significant boost in strength and one that he desperately needs.
5 Better Sage Mode
Naruto Uzumaki learned Sage Mode shortly before his fight against Pain. Ever since then, this skill has become one of his greatest assets. However, after gaining better powers, such as Kurama Chakra Mode and even Six Paths Sage Mode, Naruto relied on Sage Mode quite rarely.
As such, he didn't get to properly improve his usage of this power. After losing Kurama, Naruto needs to train in the Sage Mode arts once again and by doing so, improve its usage. An improved Sage Mode could help him get much stronger and possibly even take on an Otsutsuki once again, despite not having the power of Kurama anymore.
4 Wood Release
Wood Release is an exceptionally powerful Kekkei Genkai that belonged to the First Hokage of Konohagakure, Hashirama Senju. Using this power, Hashirama became quite a menace in combat, as seen when he could even tie fights against the likes of Madara Uchiha. Although several other characters got to wield Wood Release, later on, none did it with the same level of skill as Hashirama.
Naruto Uzumaki, having access to his cells, could end up learning Wood Release. If he does so, he'd gain one of the mightiest Kekkei Genkai in the story that would greatly aim him in battle. With its powers, Naruto would be able to completely control the terrain in battle and even absorb the chakra of those he faces in combat. Without a doubt, it'd aid him greatly as a fighter.
3 Hashirama Cells
Along with the ability to use Wood Release, Hashirama cells would also aid Naruto Uzumaki in other ways. These cells improve one's rate of recovery drastically and give more chakra to the user. Hashirama Senju, the First Hokage, was known for his near-limitless reserves of chakra. This ended up becoming one of the reasons why his cells were sought after so much by the likes of Orochimaru and even Madara Uchiha at one point.
If Naruto goes on to make use of this power, he'd gain tremendous strength and increase his chakra even more, allowing him to last longer in fights against strong enemies. Furthermore, it would also significantly boost his healing factor which has certainly weakened now that he no longer has Kurama in his body.
2 Chakra Absorption Tool
Shortly after the Momoshiki Arc, fans saw Katasuke create a prosthetic tool for Naruto Uzumaki that allowed him to absorb chakra. Although this was just a prototype, it was supposed to work similarly to how Momoshiki's Rinnegan does. Naruto tested this power in combat against his son, Boruto Uzumaki, however, he hasn't touched it since then.
Now, he needs it more than ever. Katasuke mentioned that he was still working on making this power even better, which would mean that it'll get even stronger in the future. Although the tool has the power to absorb chakra, it still needs the power to expel the absorbed chakra by amplifying it, just like Momoshiki used to do. Once completed, this tool would become a great asset for Naruto Uzumaki in combat.
1 Other Ninja Tools
With the age of shinobi growing, there are also many scientific advancements being made in the world of ninja. The two go hand-in-hand, as this has been seen on quite a few occasions in the series already. The likes of the Kara members have been greatly modified using Scientific Ninja Tools to get stronger and there is no reason why Naruto Uzumaki can't be subjected to some similar power upgrades if the need is utmost.
Thanks to Katasuke, Naruto could end up gaining some other great powers that make him even stronger in combat. There is no limit as to what scientific ninja tools can do in the story and for Naruto, if Kishimoto does end up choosing one, fans can rest assured that it would be something incredibly powerful.