The main character is Naruto for sure. In addition, depending on how the fanfiction is written, there might be a female lead from Ishgar who becomes Naruto's love interest. There could also be an antagonist, perhaps an evil wizard in Ishgar who wants to overthrow Naruto and take his godly powers. And then there might be Naruto's friends from his original world who somehow end up in Ishgar too and help him in his adventures.
There's no way to know for sure who specifically created this concept without more research. It could be a relatively unknown fan who just wanted to combine two things they liked. Maybe it started as a small idea in a fan community and gradually spread. There are so many fanfiction writers out there that it could be someone from anywhere in the world with access to both Naruto and Ishgar media.
In fanfiction, 'naruto is the second god of ishgar' could mean that Naruto has been incorporated into the Ishgar setting and given a divine status. The 'second' part might suggest that there is already one main or more powerful god in that fictional world, and Naruto is just below in terms of power or influence. His skills and traits from the Naruto series are likely to be reimagined in the context of Ishgar, perhaps with some new abilities or relationships based on the rules of the Ishgar world.
In this 'naruto god of fertility fanfiction', Naruto is surely a main character. But depending on the plot, there could be new characters created specifically for this fanfic. Maybe there's a character who is the opposite of Naruto in terms of fertility, someone who tries to stop Naruto from using his powers. And of course, his friends from the original series may also be main characters as they support or oppose his new role.
Well, Naruto is the main character for sure. However, there could be new characters introduced specifically for this fanfiction. There might be a group of animal - like ninjas who either oppose Naruto or join forces with him. There could also be a mysterious figure who has some knowledge about the 'god of animals' power that Naruto has acquired. This person could be a mentor - like figure or a potential villain. And of course, the various animals that Naruto has a connection with in this fanfiction would also be important characters, each with their own quirks and significance to the story.
The main character is Naruto, who is in the Remnant world. In addition to him, there could be some original characters created specifically for this fanfiction. They might be characters who are influenced by Naruto's presence in their world. Maybe a young trainee who idolizes Naruto and tries to learn from him, and this character could play a crucial role in the story along with Naruto and the RWBY characters.
Most likely Naruto would still be one of the main characters. Since it's related to Naruto, he'd probably be at the center of the story, dealing with the implications of the hidden god. Sasuke could also be a main character, perhaps his path intersects with Naruto's in a new way due to the hidden god's influence.
Obviously, Naruto is one of the main characters since it's a Naruto fanfiction. He would be the one with the dragon god powers. Sakura and Sasuke could also be main characters as they are Naruto's closest friends and would be involved in his journey with the new powers, either supporting him or having their own reactions to his transformation.
Obviously, Naruto would be one of the main characters since it's in the title. He's the one with the 'vampire god' transformation. There might also be his friends like Sasuke and Sakura. Sasuke could be either a rival or an ally in Naruto's new vampire - related adventures. Sakura might be concerned about Naruto's change and try to help him control his new powers.
Well, Naruto would be the main character for sure, since it's about him as the god of darkness. Sakura and Sasuke could also be important characters. They might be trying to understand Naruto's new form and powers, and either help him or be in conflict with him depending on how the story goes.
Obviously Naruto would be the main character as it's about him being the 'god of pranks'. His friends like Sasuke, Sakura, and Kakashi are likely to be important characters too. Sasuke might be the target of many of Naruto's pranks, which could add some humorous tension between them. And Kakashi, as Naruto's teacher, might be constantly trying to stop Naruto's pranks or get caught up in them.