There could be Grayfia. As a powerful figure in Rias' world, she might keep an eye on Naruto to make sure he doesn't cause any trouble. Xenovia could be involved too. Given her combat - loving nature, she would surely be interested in sparring with Naruto. Also, the Gremory family members like Sirzechs might play a role. He could be a mentor - like figure to Naruto, guiding him on how to use his powers in this new world and how to deal with the politics and power dynamics.
Issei could be involved. He might be initially skeptical of Naruto, but as they train together or fight side by side, they become friends. Akeno could also play a part. She might be curious about Naruto's powers and try to learn some of his techniques. Kiba would be another character. Since he has his own combat abilities, he and Naruto could have friendly competitions to see who is stronger in different aspects.
The plot might involve Naruto trying to adapt to the new environment of being related to Rias. Since he has his own strong sense of justice from his ninja world, he could conflict with some of the more underhanded tactics in Rias' world. But in the end, they work together to overcome difficulties. For example, when facing a powerful enemy that neither of them could handle alone, they combine Naruto's ninjutsu and Rias' devil powers to defeat it.
One possible fanfiction idea could be that Rias' sick brother is a key factor in a power struggle within their supernatural world. Naruto, being an outsider with his own set of skills and values, could get involved. Maybe he forms an alliance with Rias to protect her brother from those who would use his illness to their advantage.
Well, Naruto being the son of Rias could have some interesting allies. Firstly, Rias herself would be a great ally, teaching him about the devil society and how to use his powers. Then, there could be other devil clans that are friendly to Rias' clan and would support Naruto. In the ninja world, his old sensei or comrades who respect his decision to embrace his new identity could be his allies. Also, there might be some mythical creatures in the devil realm that recognize Naruto's pure heart and decide to fight alongside him.
The plot could involve Naruto using his knowledge of chakra to diagnose Rias' brother's illness. He might discover that it's not a normal sickness but something related to the supernatural nature of their world. For example, his chakra flow could be disrupted by a dark magic spell.
The devils that oppose Rias' group could be the antagonists. They might see Naruto as an unknown threat and try to eliminate him. Also, there could be some dark magic users who don't want Naruto interfering in their plans in Rias' world.
Well, it could be a story full of interesting dynamics. Naruto's energetic and determined personality would contrast with Rias' more composed and strategic nature. Maybe Naruto, as Rias' little brother, would bring a new kind of chaos to the supernatural world she inhabits. He might introduce some of his ninja skills and values into her group, like loyalty and never giving up. It could also lead to some really cool fight scenes where Naruto uses his shadow clones and Rasengan against the devils and other creatures in Rias' world.
Yes, there might be. Fanfiction is a vast world where all kinds of crossovers and unique relationships are explored. You can start by looking on popular fanfiction websites like Fanfiction.net or Archive of Our Own. Just search for the relevant tags or keywords to find stories that revolve around this concept.
Yes, there might be some fanfiction exploring such a unique crossover concept. In the world of fanfiction, writers often come up with creative and unexpected relationships between characters from different series. They might do this to create new storylines, explore different character dynamics, and engage readers who are fans of both 'Naruto' and the series where Rias is from (presumably 'High School DxD').
There could be the other members of Rias's peerage. In some fanfictions, they might be forced to choose sides between Rias and the OC. For example, Akeno might be torn between her loyalty to Rias and her growing respect for the OC's abilities.
Well, in a 'Naruto is Rias' brother' fanfiction, there would be a lot of potential for character development. Naruto, being from a world where he had to fight for his place and for the safety of his village, would bring that same determination to protect Rias and her friends. He might be shocked at first by the devil society's hierarchy and customs, but would gradually find ways to fit in and make changes. Rias, on the other hand, would have a powerful and loyal brother by her side. They could face off against common enemies, like other devils who oppose Rias' ideas or angels who see Naruto as an unknown and dangerous element. The fanfiction could also explore their family backstory, how they were separated in the first place and what it means for them to be reunited now.