The exploration of different worlds or dimensions is also a theme. Since Ophis has connections to different realms, fanfictions often take Naruto and Ophis on adventures through these strange and new places. This allows for a lot of creativity in terms of world - building and the discovery of new and unique things.
A lot of Naruto x Ophis fanfictions also deal with the concept of redemption or change. Ophis is often portrayed as a rather mysterious and powerful being in High School DxD. In the fanfictions, Naruto might influence her to see things in a different way, perhaps to be more empathetic or to use her power for good. And vice versa, Ophis could introduce Naruto to new concepts from her world that could change his perspective on things.
One main theme is power. Naruto already has his own set of powers, and when combined with Ophis' abilities, the exploration of new power levels and how to control them is a big part. For example, in some fics, Naruto might struggle to master a power given by Ophis.
One common theme is power. Ophis being a very powerful character, many fanfictions explore how her power is perceived and used in different situations within the high school setting.
At first, Naruto might see Ophis as a powerful ally he needs to understand in order to protect his world. He would try to approach her with respect. Ophis, seeing Naruto's pure heart, would allow him closer. They would then go through various challenges together, like facing enemies that threaten both their existences. During these trials, they would rely on each other, and Naruto's positive attitude would start to melt Ophis' cold exterior. Their bond would strengthen over time until they realize they can't live without each other and decide to get married.
Love and acceptance is also a very common theme. Given their different natures, the fanfics often explore how they come to love and accept each other for who they are. This can involve Issei accepting Ophis' more otherworldly aspects and Ophis learning to value Issei's human qualities like his compassion and determination.
One common theme is the exploration of their relationship dynamics. Given that Ophis is a very powerful being and Issei has his own growth journey in the series, fanfics often delve into how they interact and influence each other's development.
In this fanfiction, perhaps Naruto is transported to a dimension where Ophis is a powerful figure. Naruto, with his strong sense of justice, tries to understand Ophis' motives. He may initially be in awe of her power but then realizes that there are some dark aspects to her actions. He then has to decide whether to side with her or oppose her while also trying to find a way back to his own world.
The plot might involve Naruto exploring his new family connection to Ophis. He could go on a journey to learn more about Ophis and his own origins. Along the way, he may encounter other characters who either help or oppose him because of his relation to Ophis. For example, some might fear his newfound power while others could see him as a key to some greater prophecy or plan.
One possible plotline could be Naruto, as a male, having some kind of special connection with Ophis. Maybe he discovers a power within himself that is related to Ophis' nature. For example, he could gain the ability to control a certain type of magic or energy similar to what Ophis has.
Well, it could be that Fem Naruto, with the power or characteristics of Ophis, has to face the challenges in the Naruto universe in a different way. Maybe she uses Ophis - like powers to defeat stronger enemies or to gain respect in the village that once shunned Naruto.