One idea could be an OC Devil who has a unique power related to time manipulation. For example, they can freeze time briefly in battles, giving them an edge. Another could be an OC Devil from a long - lost noble family trying to reclaim their family's honor and status within the Devil society. They would have to face many challenges and rivalries along the way.
One possible scenario in this fanfiction could be Naruto having his unique ninja skills in the Highschool DxD world. His godlike abilities might make him stand out among the devils and other supernatural beings. He could use his shadow clone jutsu for various strategic purposes, like infiltrating devil strongholds or getting out of tricky situations during the school's chaotic events.
There could well be. Fanfiction writers often like to explore crossovers and unique concepts. However, not all fanfic writers might be interested in combining Naruto with 'Highschool DxD' in a certain way, so there are likely to be some that fit the 'Naruto not a devil highschool dxd fanfiction' idea. You might have to dig a bit through different fanfic archives to locate them.
An OC (Original Character) in a Highschool DxD fanfiction having the Rinnegan could be an extremely powerful and unique addition. The Rinnegan, from the Naruto universe, brings a whole set of abilities like the Six Paths powers. In the context of Highschool DxD, this OC could use these powers in various ways. For example, the ability to see chakra could be translated into seeing the magical energy in the DxD world. They could use the gravitational powers of the Rinnegan to manipulate the environment during battles against devils, angels, or fallen angels. It would make for a very interesting and overpowered character in the Highschool DxD fanfiction setting.
Give your OC Devil a distinct personality trait. For example, if they are extremely curious, it can lead to all kinds of interesting situations. Also, a unique appearance helps, like having purple - tinted horns or a tail with a special pattern.
One characteristic could be that the story remains true to the Naruto universe's tone and themes. It would likely have Naruto dealing with his own set of challenges like fighting against the Akatsuki or protecting his village. It wouldn't introduce the harem - like or devil - based elements from 'Highschool DxD'. Also, the characters would be from the Naruto world, with their own personalities and abilities intact, without any 'Highschool DxD' - influenced changes.
The OC, as the Son of Sparda, could fit in by being a new and powerful entity. He might be initially seen as an outsider, but his powers would quickly draw attention. He could become involved in the power struggles between the different factions in Highschool DxD. For example, the devils might try to recruit him, while the angels might be wary of his presence. His unique abilities would also make him a valuable ally or a fearsome opponent. And in the high school setting, he could be a bit of an enigma to the other students, both human and supernatural.
One great fanfiction could be where the OC has a unique power that Akeno is initially intrigued by. For example, the OC might have the ability to control light in a different way than the devils in the Highschool DxD universe. This could lead to a series of adventures where Akeno and the OC team up to face various challenges. They could start off as just acquaintances but gradually develop a deeper bond as they fight side by side.
A plot could involve the mute OC being a new transfer student in the school. Their muteness makes them an object of curiosity and some characters might initially misjudge them.
One possible aspect could be the unique abilities that Eve might possess in her reincarnated form. In Highschool DxD fanfiction, new characters often bring fresh powers. For example, Eve could have a special power related to light or healing, which would make her a valuable asset to the group. This could also lead to interesting storylines where she has to learn to control her powers while also dealing with the typical Highschool DxD chaos of devils, angels, and fallen angels.