In this fanfiction, Naruto would probably be the catalyst for change. His presence alone would disrupt the normal flow of things in the High School DxD school. He could introduce new jutsu and training methods that the students there might find fascinating. His relationship with Fem Kyuubi would also play a part, as he might help her come to terms with her identity and power in this new and strange environment.
His role could be that of a protector. Given his nature of protecting his friends in the Naruto series, he would likely do the same in the High School DxD world. He could protect Fem Kyuubi from those who might want to take advantage of her power. Also, he could be a bridge between the different species in the school, using his understanding of different types of people from his own world.
If Naruto had Kyuubi's power in the High School DxD universe, things would be chaotic at first. His presence would be a shock to the different factions. The devils would likely try to either recruit him or eliminate him. But Naruto, with his strong will and Kyuubi's power, could form new alliances. He could teach the students at the school some of his ninja ways and in turn learn about the magic and powers in that world. His Kyuubi - enhanced abilities would make him a formidable opponent in the Rating Games.
The character could be a catalyst for change. The EMS gives them access to powerful abilities. In the High School DxD world, which is often about power struggles and hierarchies, their presence could disrupt the status quo. They might inspire other characters to strive for greater power or to question the existing power structures. For example, if they use their EMS to defeat a powerful devil who has been oppressing others, it could start a movement among the weaker characters to stand up for themselves.
Well, the story could start with Naruto and Fem Kyuubi being transferred to the High School DxD school. Naruto might struggle to adapt to the different rules and social hierarchy there. The Fem Kyuubi, on the other hand, could use her charm and wits to navigate through the new environment. Their relationship could evolve as they face challenges together, like dealing with the various factions in the school.
She might be a mediator between different factions. Since she has experience dealing with different groups in the Naruto world, she could try to bring peace between the devils, angels, and other races in the DxD world. Also, her unique sense of justice could influence the characters in DxD to be more morally upright.
Firebrand could be a student in the High School DxD setting who has a strange connection to the Naruto world. Maybe they have dreams or visions of the Naruto world and start to develop ninja - like abilities in the High School DxD world. This could lead to them being an outcast at first, but as they grow in power, they become a key figure in protecting the school from threats that are both from the High School DxD universe and potentially threats that have some connection to the Naruto world.
A 'Naruto in High School DxD' fanfiction could involve Naruto being transferred to the DxD school. He would stand out immediately with his orange jumpsuit. His Rasengan could be a very powerful move against the devils and angels in that universe. And his sense of justice would likely lead him to get involved in all the power struggles and protect the weak, just like he did in his own world.
Well, he could be a powerful antagonist. His skills and power from the Dragon Ball universe would make him a formidable foe in the High School DxD world. He might be interested in the power of the devils and angels there and try to take it for himself.
Goku Black might become a sort of anti - hero. He has his own sense of justice (albeit a twisted one in his original story). In the High School DxD world, he could oppose some of the more corrupt elements of the different factions while also causing trouble for the main characters as they try to figure out his motives. For instance, he could see the way some devils treat humans in the DxD world and decide to take matters into his own hands, but not in a way that the main characters would necessarily approve of at first.
In a Naruto and High School DxD fanfiction, there could be a scenario where the protagonists of both stories meet in a neutral dimension. Issei from High School DxD might be intrigued by Naruto's ninja skills and determination. Naruto, in turn, could be curious about Issei's Sacred Gear. They could start training together, sharing their knowledge and skills, and ultimately have to face a common enemy that threatens both their worlds.
A 'Naruto is God' High School DxD fanfiction would be full of interesting crossovers. Naruto's sage mode could have a different interpretation in the High School DxD world. He might use it to sense the auras of different supernatural beings more clearly. His relationship with the female characters in High School DxD could also be an interesting aspect. Maybe some of them would be in awe of his god - like status, while others might challenge him. And his moral code, which is influenced by his experiences in the Naruto world, would likely clash or blend with the values of the High School DxD world. This could lead to many complex and engaging storylines as he tries to navigate this new universe while being a god - like figure.