Since it's a 'naruto rasen ring fanfic', Naruto is likely one of the main characters. However, new characters might be introduced as well. For instance, a mysterious figure who guards the rasen ring could be a main character. Or perhaps a young ninja who discovers the power of the rasen ring and looks up to Naruto for guidance on how to use it in relation to the Rasengan.
Typically, in a fanfic related to Naruto, Naruto would be a main character. If the rasen ring is a new element, other characters like Kakashi could be involved as a mentor figure. Also, if the story is about a new generation, Boruto might make an appearance to learn about the significance of the rasen ring from Naruto.
A 'naruto rasen ring fanfic' may be a story that combines the iconic Rasengan from the Naruto series with the concept of a ring. It could be that the ring is a symbol of a particular clan or group, and the Rasengan has some connection to it. This could create a plot where the main character has to prove their worth by using the Rasengan in relation to the ring, like in a coming - of - age story within the Naruto universe.
It could be a rogue ninja who has developed a counter - technique to the Rasen Shuriken. He aims to use this to defeat Naruto and prove himself as the strongest. This antagonist might have a personal vendetta against Naruto or simply be power - hungry.
Obviously Naruto would be one of the main characters. There might also be his friends like Sasuke and Sakura. But since it's a fanfiction involving a special millennium ring, there could be new characters created specifically for this story who are also important.
I'm not entirely sure as I haven't read the 'as the ring went south fanfic' in detail. But usually in such stories, there could be a hero - like figure who is leading the journey south. Maybe there's also a wise old character who gives advice along the way.
There's no way to be certain without reading it, but perhaps there's a female lead who is somehow connected to the ring. Maybe she has a special ability that is awakened by the ring, and there could be a male character who helps her on her journey with the ring. There could also be an antagonist who wants to steal the ring for their own malicious purposes.
It could be Orochimaru from an earlier time. Since he was always after power and secrets, Naruto's knowledge of the Rasen Shuriken and his time - traveling abilities would be a huge threat to Orochimaru's plans. Orochimaru might try to steal Naruto's jutsu or use him to gain more power.
The main characters are Bones and Galia. Bones, who is likely to be a complex character with his own set of values and emotions, is focused on getting the right engagement ring. He may have to overcome various obstacles in the process. Galia is the woman Bones loves, and she represents the future that Bones is looking forward to. Their relationship forms the core of the fanfic, and the engagement ring is just a symbol of their love and commitment in this story.
There is also an old and wise wizard. He guides the hero in his journey regarding the rings, using his knowledge and magic. He has a deep understanding of the power of the rings and the danger they pose. For example, he might know the history of how the rings were created and what their true purpose is. He tries to ensure that the power of the rings is not misused by the wrong hands.
Since I don't know the exact 'the ring story', it's hard to say. But generally, there could be a finder of the ring. Maybe a young adventurer or a curious child.
I'm not sure specifically as there are many novels that could be called 'the ring novel'. But generally, there could be a protagonist who discovers the ring and gets caught up in its mystery. There might also be an antagonist who wants to use the ring's power for their own evil purposes.