Kakashi could also be a great help. With his vast experience and wisdom, he could guide Naruto in understanding the implications of becoming a new species. He might be able to teach Naruto how to control any new powers that come with the transformation and how to deal with the potential social isolation.
Maybe Naruto could gain some unique powers. For example, if he becomes a new species like a dragon - like being, he might be able to fly and breathe fire, which would completely change the way he battles and protects the village.
He probably gains the ability to control the chakra of the Kyuubi more freely. This could mean enhanced strength, speed, and reflexes. He might also be able to use some of the Kyuubi's unique jutsu like the Tailed Beast Ball. His healing factor could be improved as well, allowing him to recover from injuries faster.
They can be introduced as allies or enemies of the main characters. For instance, if the new species has a unique skill, like the ability to control a powerful energy source, the Jedi or Sith could either try to recruit them or fight against them. The new species could also be added as a part of a political plot. Maybe they are being oppressed by an existing galactic power and need the help of the heroes to gain freedom.
The Aquanites could be a new species. These are semi - aquatic beings with gills and webbed hands and feet. They live in the vast oceans of uncharted Star Wars planets. Their culture could be centered around underwater cities and they could have a unique form of communication using sonar - like signals. They might be in conflict with species that over - fish their waters in fanfiction stories.
It could be the old enemies who see Naruto's new form or role as a threat. Maybe Orochimaru, who is always after power, would try to stop Naruto or take advantage of his new state. He might think Naruto's power in this apocalyptic scenario can be harnessed for his own evil purposes.
Well, perhaps Naruto becomes the new apocalypse in a sense that he has been corrupted by some powerful evil force. His friends would then be in a dilemma of having to either stop him or try to save him. His transformation could also lead to a new power hierarchy in the ninja world, with everyone fearing his new, unpredictable abilities.
One possible new character could be a young orphan with a hidden talent for ninjutsu. Naruto, having been an orphan himself, takes the kid under his wing. This new character could have a unique power that is related to illusions but in a much more advanced and dangerous way than the normal genjutsu. Another new addition could be a ninja from a rival village who, after seeing Naruto's growth, decides to join him instead of fighting against him. This character could bring with him the knowledge of the rival village's secret ninja strategies.
If Naruto becomes a new bijuu in fanfiction, he might gain even more power. He could have unique abilities that are a combination of his existing skills and the power of a bijuu. For example, his already strong chakra control might be enhanced, allowing him to perform more powerful jutsus with less effort. Also, his connection to other characters would change. His friends might view him with a mix of awe and concern, as they would have to adapt to this new, more powerful Naruto.
Naruto might gain the power of shikai and bankai. Shikai is the first release of a zanpakuto's power, and bankai is the ultimate form. Naruto, with his determination and strong will, would strive to master these forms. Shikai could give him new attacks and defenses, while bankai could make him an extremely powerful force. For example, his bankai could combine his ninjutsu skills with the zanpakuto's power in a unique and devastating way.