In many 'Cold Genius Naruto Fanfiction', Kakashi can play a significant role. He might be the one to notice Naruto's cold - related powers first and help him develop them. Another often - seen character is Hinata. She could be Naruto's love interest while also being involved in his journey as a cold genius, perhaps providing emotional support.
Obviously, Naruto himself is often a main character. His natural talent and determination in the original series can be translated into the 'genius gamer' aspect. Sasuke might also be a key figure, as his rivalry with Naruto can be reimagined in the context of the gaming elements. Sakura could be there too, perhaps using her medical skills in a new way within the gaming - influenced story.
Often, Naruto himself can be a main character in Naruto cold eyes fanfiction. The story could explore how he interacts with a character who has cold eyes. Another common main character could be a new, original character created specifically for the fanfiction, who has these cold eyes and has a significant role to play in the Naruto - inspired world.
The Akatsuki members also often make appearances. Their mysterious and powerful nature makes them interesting to write about in fanfiction. In a 'naruto crazy genius' fanfiction, Naruto might interact with them in unexpected ways. For example, he could use his new - found genius to outwit them in battles or even form alliances with some of them to achieve a greater good, which would completely change the dynamics of the Naruto story.
It's hard to say without reading it, but it could be Naruto himself if the story is about a secret aspect of his genius that hasn't been explored in the original. Maybe he has some hidden intellectual ability that is only revealed in this fanfiction.
There could be original characters created specifically for this fanfiction. Maybe a mysterious mentor figure who helps Naruto understand and control his 'dark genius' side. This character could have their own backstory and motives that tie into the overall plot.
The main characters can include the gunsmith, who might be an outsider to the traditional ninja world but has a unique skill set. Another could be a ninja who becomes the gunsmith's protector or partner. For example, Sasuke could be interested in these new firearms as a way to enhance his own power. And sometimes, there are original characters created specifically for the fanfiction, like a rival gunsmith who tries to outdo the main gunsmith in creating the most powerful weapons.
Often, there are also antagonist assassins who are main characters in a sense. They drive the plot by creating conflict. These assassins could have their own motives, like working for a powerful and shadowy organization. Their backstories, which might include things like being orphans trained from a young age to be killers, can add depth to the fanfiction.
Naruto himself could be a main character in such fanfiction. Maybe he gets framed for pickpocketing and has to clear his name while also dealing with the real pickpocket who is causing chaos in the village.
Obviously, Naruto is one of the main characters. Since it's 'naruto insane genius fanfiction', he's likely to be the central focus with his extraordinary intelligence being highlighted. Sasuke is also often a main character as his relationship with Naruto is a crucial part of the Naruto universe. Sakura might also be there, and she could be shown in new ways, perhaps learning from Naruto's genius or being part of his grand plans. Kakashi could also play an important role, acting as a mentor or sometimes being amazed by Naruto's insane ideas.
Orochimaru is another possibility. He is already somewhat of an evil genius in the original Naruto series. In a fanfiction, he could be further developed as the main character, perhaps with his experiments taking on even more extreme and far - reaching consequences. His actions and plans could be the central focus of the story, with other characters either trying to stop him or being caught up in his schemes.