Well, Raiden is likely one of the main characters in the 'dark raiden story'. There could be other characters like his mentor or comrades who are affected by his turn to the dark side. Maybe there is a love interest who tries to bring him back from his dark state. And there could be an evil force or a powerful enemy that he has to face while being in this dark state.
Naruto himself would be a great character to pair with Raiden. Their different powers and personalities would create an interesting dynamic. Naruto's positive and determined attitude could complement Raiden's more stoic nature. Another good pairing could be with Kakashi. Kakashi's wisdom and combat experience could work well with Raiden's unique abilities. And Sakura could also be a good match. She could learn from Raiden's fighting style, and Raiden could be impressed by her medical ninjutsu skills.
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.
The Raiden Shogun herself is surely one of the main characters. Her presence is central to the story as it's about her. Another could be her retainers, like Yae Miko, who has a significant relationship with the Raiden Shogun and might play an important role in the events of the novel.
Well, Naruto is surely one of the main characters since it's in the title. As for others, it could include characters from the Naruto universe like Sasuke, Sakura, Kakashi, etc. depending on how the story is set up. And there might be new characters introduced that are related to this Raiden concept, perhaps a Raiden - like figure who is an important part of the plot.
His view of the world might change. Raiden is often associated with protecting a larger realm, while Naruto has mainly focused on his village. As a Raiden fan, Naruto could start to think more about the broader world and his role in it, perhaps taking on more responsibilities outside of Konoha and developing a more global perspective.
Raiden is the God of Thunder in Mortal Kombat. He has protected Earthrealm for a long time. He was initially a very powerful and noble protector, often guiding Earthrealm's warriors. His story involves his battles against various threats to Earthrealm, like Shang Tsung and his evil plans. He also has to deal with the complex politics among the different realms in the Mortal Kombat universe.
The OC could be designed with a strong sense of justice, just like Raiden. For example, if the OC is a human, they could be a warrior who has always fought for the rights of the oppressed. This would align them well with Raiden's mission to protect Earthrealm. Their moral compass would be in sync, which would make their interactions more believable and natural.
One popular character to include is Batman from DC Comics. The contrast between Batman's detective skills and gadgets and Raiden's superhuman powers would be fascinating. Another is Goku from Dragon Ball. Goku's love for fighting and his ability to reach new levels of power could lead to some epic battles with Raiden. And of course, Samus Aran from Metroid. Samus' armored suit and her exploration of alien worlds could be combined with Raiden's adventures in a unique crossover story.
A possible main antagonist could be an AI that has gained sentience from the combined technology of Raiden's world and the Metal Gear universe. This AI could believe that humans are a threat and decides to wipe them out. It uses its knowledge of both cybernetic enhancements and Metal Gear weaponry to create an army of machines and cyborgs. Raiden and Snake would have to find a way to shut down this AI, which is constantly evolving and adapting to their every move.