Naruto is the central character as the title implies. His mother, whose identity and connection to the Kyuubi are important aspects of the story. Jiraiya could also be a main character as he was Naruto's teacher and mentor. He might help Naruto understand his heritage better. And then there could be new characters created specifically for this fanfiction, perhaps other ninja from different clans who are either friends or foes depending on how they view Naruto's connection to the Kyuubi.
In this fanfiction, it could be that Naruto's mother being associated with the Kyuubi gives him a different perspective on the world. He might struggle with the expectations that come with such a powerful heritage. There could be a plot where he has to prove himself not just as Naruto, but as the son of a female with a connection to the Kyuubi. His journey could include learning about his mother's past and how it ties into the overall story of the ninja world.
Well, it's likely that we'll see Naruto's sensei, Jiraiya, in this fanfiction too. He could have known about Naruto's 'son of nature' aspect all along and left some clues or teachings for Naruto to discover later. There could also be some ancient shinobi who had a similar connection to nature in the past and their spirits or legacies could play a part. And don't forget the animals! Maybe a giant eagle or a group of intelligent foxes could be characters that assist Naruto in his adventures related to his nature - based powers.
There could also be new characters introduced, like other Shinigami or beings related to the Shinigami world. For instance, a Shinigami who is Naruto's father figure or a spirit guide who helps Naruto understand his powers. These new characters would add more depth to the story and bring in new conflicts and relationships in the fanfic.
Well, the Akatsuki members could be antagonists. They might be interested in the treasures or powers that Naruto, as Jack Sparrow's son, has access to. Tsunade could also play a role, perhaps as a mentor or someone who is skeptical about Naruto's new pirate - like ways. Kakashi might join Naruto on his adventures, using his Sharingan to help in combat situations at sea.
Perhaps there could be some of Kaguya's old allies or servants who come back to serve Naruto. Or new villains who are related to Kaguya's past enemies.
Sakura is often a main female character in such fanfictions. She might be portrayed as having a different relationship with Naruto, who is the ladies man in this case. Maybe she's initially jealous of all the female attention he gets but then realizes her true feelings for him.
Since it's 'naruto son of dragons fanfiction', Naruto is the central figure. There could be dragon elders or dragon - shaped beasts as important characters. Maybe there's a dragon mentor for Naruto who teaches him special skills. Also, characters from the original Naruto series like Sasuke and Sakura could still be important, but their roles might be adjusted according to Naruto's new dragon - related identity.
Obviously, Naruto would be one of the main characters. And since it's about him being the son of Roshi, Roshi would also be a central figure. There might also be other Naruto - series regulars like Sasuke, Sakura, Kakashi etc. depending on how the fanfiction writer decides to incorporate them into the story.
The main characters would surely include Naruto. Then, depending on the direction of the fanfiction, characters like Jiraiya could be important as he might be the one to help Naruto understand and control his dark side. There could also be some dark - themed characters that are part of Naruto's heritage or the source of his 'son of darkness' status. And of course, his friends, even if they are initially wary of him, would still be key characters as they react to Naruto's transformation or discovery of his new identity.
Obviously, Naruto would be one of the main characters since it's about him being the son of Raiden. Raiden himself might also be a major character, perhaps making appearances in Naruto's life to guide him or pass on his powers. There could also be the regular Naruto characters like Sasuke and Sakura, who would interact with Naruto in this new scenario and be important to the story.