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').
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.
Yes, there are some. You can try searching on fanfiction websites like FanFiction.net or Archive of Our Own. Just type in 'Naruto brother of Rias' in the search bar, and you'll likely find several stories to explore.
One possible plot could be that Naruto, as Rias's brother, brings his ninja skills to the world of High School DxD. He might use his jutsu to protect Rias and her peerage from various threats, like the devils from other factions or rogue exorcists. And along the way, he could also teach some of his ninja techniques to the members of Rias's peerage.
In such a fanfiction, at first, there would be shock and disbelief on both sides. Naruto, being from a world of ninjas, and Rias, from a world of magic and devils. But as they get to know each other, they would discover similarities in their determination and loyalty. The story could involve Naruto using his shadow clones to help Rias in her battles or in dealing with the politics of her world. And Rias could introduce Naruto to new forms of power and magic that he could learn from. It would be a story of two different worlds colliding and two characters growing closer as siblings.
In a fanfiction where Naruto is Rias' brother, the Naruto storyline would be altered significantly. Naruto's nature as a person might change due to the influence of the devil society. He may become more sly or strategic in the way devils are. His fighting style could incorporate more magic - like elements from the DxD world. His backstory would now involve being part of a devil family. His relationships with his friends in the Naruto world would be less prominent as he'd be more involved with the devils. For example, instead of going on missions in the ninja world, he'd be involved in devil - related tasks to protect his sister and their family's status.
His character can be developed by giving him challenges. For example, he could be put in situations where he has to choose between loyalty to his family and what he believes is right. This would force him to grow morally. Also, having him face opponents stronger than him in battles would make him train harder and develop his combat skills.
They could go on adventures to stop powerful demons that threaten the balance of the DxD world. Naruto's combat skills and Rias' leadership would make them a formidable team. They might also travel to different dimensions in search of rare items or knowledge. For instance, they could explore a dimension where there are unique forms of magic that Naruto could learn to combine with his chakra.
Well, considering the devilish nature of Rias' world, Naruto could gain the power of flight, which is not something he has in his original ninja world. He could also gain the power to resist holy attacks, as devils are often weak against holy elements. Another power could be the ability to create and control demonic flames. These new powers would not only change his combat capabilities but also how he is perceived in this new fanfiction world.
It's quite possible. Fanfiction writers often come up with interesting and unexpected concepts. Since Naruto and the world of Rias have their own distinct fan bases, combining them in a story where Naruto is a fan of Rias can add a new and exciting twist. You could also check fan - run forums dedicated to either Naruto or High School DxD to see if anyone can point you in the direction of such a fanfiction.