In fanfiction, Naruto creating Chidori could be possible through some creative plot devices. Maybe he was taught by Sasuke in an alternate universe where they teamed up earlier. Or perhaps he discovered a scroll that had the knowledge of Chidori and was able to learn it on his own with his determination and quick - learning ability.
One consequence could be a shift in his relationships. Sasuke might be both impressed and a bit threatened. Their rivalry could take on a new dimension as Naruto now has a jutsu similar to Sasuke's signature move. Also, the village might view Naruto in a new light, as he's mastered a foreign - seeming jutsu. It could make him seem more versatile and dangerous to enemies.
In a more creative fanfic, an ancient ninja who was the originator of the Chidori technique could appear. This ninja could be brought back to life through some sort of magic or jutsu. He sees Naruto's pure heart and decides to pass on the Chidori knowledge to him, believing Naruto will use it for good.
One possible scenario could be that Naruto learns the Chidori from Sasuke in a moment of truce. Sasuke, realizing Naruto's determination to become stronger, decides to teach him this powerful jutsu. Another could be that Naruto discovers a scroll that contains the secrets of the Chidori and through his own hard work and study, he manages to master it. Or perhaps, a new character appears who has knowledge of the Chidori and trains Naruto in it as part of a greater plan to defeat a common enemy.
If Naruto creates a lightsaber, it could be related to his connection with Kurama. Kurama's chakra is extremely powerful. It's possible that this chakra could be harnessed in a way that can mimic the energy source of a lightsaber. Naruto, being the creative and adaptable ninja he is, would then figure out how to shape and control this new form of energy into a blade, much like a lightsaber. And he would surely use it to protect his friends and the Hidden Leaf Village.
In fanfiction, Naruto could create Xenomorphs through some sort of jutsu gone wrong. Maybe he was experimenting with a new form of shadow clone jutsu and accidentally combined it with some dark chakra that had mutagenic properties. This could result in the creation of Xenomorph - like creatures.
Sasuke could be Naruto's teacher. Since Sasuke is a master of the Chidori, he might decide to teach Naruto as a way to make Naruto a more formidable ally. They have a complex relationship, and this could be a way to strengthen their bond.
In many Naruto fanfictions, the Chidori - Rasengan combo is often portrayed as an extremely powerful and unique move. It combines the piercing nature of the Chidori with the rotational and explosive force of the Rasengan. Some fanfictions might have Naruto or Sasuke (or both in some cases) creating this combo during a crucial battle against a powerful enemy, like a new Akatsuki member or a rogue ninja from another village. This combo is usually described in great detail, with the lightning - chakra of the Chidori surrounding and enhancing the Rasengan, making it not only more destructive but also having an added effect like paralysis due to the electricity.
It could be Kakashi. Since he's already Naruto's teacher and he knows both techniques. He could guide Naruto in understanding the intricacies of the Chidori, like how to form the lightning - chakra in his hand, and for the Rasengan, he could give more advanced tips on chakra control.
In a fanfiction like this, the plot might involve Naruto struggling to master both techniques. He could start by observing Sasuke use the Chidori and then try to incorporate its lightning - based power into his own jutsu. For the Rasengan, he might have new insights while training, perhaps finding a way to combine it with the Chidori for an even more powerful attack. Along the way, he would face challenges like controlling the chakra flow for both techniques and dealing with opponents who are also after these powerful jutsus.
Well, if Naruto were to create an Akatsuki fanfiction, one way the storyline could develop is by having Naruto try to understand the motives of the Akatsuki members more deeply. He might explore the idea of redemption for some of them. For example, he could write about how Pain, after seeing the destruction he caused, might have a change of heart. Naruto could also create scenarios where the Akatsuki members interact with the villagers of Konoha in a more positive light, like how Sasori could use his puppet - making skills to help the kids in the village create toys instead of weapons.