One plot idea could be that Naruto is somehow transported to the world of Highschool DxD and meets Ophis. Maybe he has to help the characters in Highschool DxD deal with a threat using his ninja skills, and in the process, he forms an alliance with Ophis.
Another interesting plot could involve a power - sharing or power - exchange concept. Since Naruto has his chakra and unique abilities, and the characters in Highschool DxD have their own powers like Sacred Gears, and Ophis is extremely powerful in her own right. A fanfiction could explore what happens when their powers interact or are combined. For instance, Naruto's Rasengan combined with a Sacred Gear's power or Ophis' dragon - like abilities.
A more character - driven plot could be about Ophis being curious about Naruto's strong will and determination, which is different from the characters she usually encounters in the Highschool DxD world. She decides to study Naruto and in the process, Naruto tries to understand the complex world of Highschool DxD and its power dynamics. This could lead to a series of events where Naruto's values start to influence the characters in Highschool DxD and vice versa.
One plot idea could be Naruto being transferred to the Highschool DxD world and having to adjust to the new school environment while also dealing with the supernatural elements. He could form an unexpected friendship with Ophis, perhaps over their shared experiences of being different from the norm in their respective worlds.
One interesting plot idea could be the Son of Ophis struggling to fit into the world of Highschool DxD. He might have powers that are both a blessing and a curse. For example, his powers could attract unwanted attention from various factions in the supernatural world, leading to constant battles and challenges.
One interesting plot idea could be Issei and Ophis going on a journey through different dimensions to find a way to strengthen their bond. Maybe they encounter various mythical creatures and have to overcome challenges together. Another could be a situation where they are forced to hide their relationship from the other characters in the Highschool DxD world, adding a bit of secrecy and drama.
A great plot twist for this fanfiction could be that Ophis is actually a reincarnation of an ancient and powerful ninja from the Naruto world. Her appearance in the Highschool DxD world was part of a grand plan to gain new powers and then return to the Naruto world to fulfill a prophecy. This would completely change the dynamics of the story and the relationships she has with the characters in both universes.
Well, a plot could revolve around a mystery that involves both worlds. Maybe there is an ancient artifact that has the power to disrupt the balance between the Naruto universe and the Highschool DxD universe. Characters from both sides have to work together to find and protect this artifact. This would lead to a lot of character development as they learn about each other's cultures and values while on this quest.
One possible plot could be that Naruto somehow gets transported to the Highschool DxD world. He meets Ophis and initially they are at odds because of their different natures. But as they interact more, they start to understand each other. Naruto's determination and Ophis' power could lead to them teaming up against common enemies in the Highschool DxD universe, and their relationship could develop from there into a romantic one.
Yes, there might be such fanfictions out there. Fanfiction often combines different fictional universes in creative ways. However, not all of them are well - known or of high quality. Some might be more focused on the unique interactions between the characters from Naruto and Highschool DxD, exploring how their different powers and personalities would mesh in an unexpected relationship.
In a Highschool DxD - Naruto crossover fanfiction with Ophis, she could form an alliance with some of the Akatsuki members. They might be interested in her power and knowledge. Ophis could use this opportunity to learn about the unique chakra system in Naruto. This could lead to a series of battles and power - up scenarios as she tries to adapt to this new world and the Akatsuki tries to use her for their own goals.
One idea could be that Naruto somehow gets transported to the High School DxD world and has to deal with the devils and angels there while still having his ninja skills. He might use his shadow clone jutsu in unique ways during battles in the new world.
One idea could be a crossover where Naruto characters end up in the Highschool DxD world and have to adapt to the different rules regarding magic and devils. For example, Naruto could use his chakra in unique ways against the devils' powers.