Lucifer in this fanfiction could be depicted as a complex character. He's likely to be extremely powerful, with a commanding presence. His intelligence would be sharp, always strategizing and thinking several steps ahead.
Lucifer could be shown as having a sense of humor, albeit a rather dark one. He might find amusement in the chaos that often surrounds the events in Highschool DxD. He could also be a bit of a loner, not fully trusting anyone, as his power and status make him a target. His character could be a mix of pride, power, and a touch of vulnerability that he tries to hide.
The OC could have a unique appearance, like having heterochromatic eyes, one gold like Lucifer's and one a deep purple. Their hair could be a color not seen often in the series, such as silver. And they could have a special mark on their body that is related to their power or connection to Lucifer.
The OC would first need to understand Lucifer's powers. They might have to learn how to control the demonic energy that comes with being Lucifer. It could be a struggle at first, like learning to walk again. For example, Lucifer has the power of manipulation and the OC would need to figure out how to use it without causing chaos right away.
A fanfiction idea could be that Lucifer from the Highschool DxD universe somehow ends up in the Naruto world. In the Naruto world, he could be seen as a powerful and mysterious figure. He might interact with the ninja clans and shinobi, and his powers could be both feared and respected. He could also have some kind of connection with the tailed beasts or the Sage of Six Paths. The story could revolve around how his presence disrupts or changes the balance of power in the Naruto world.
One popular type of fanfiction about Vali Lucifer in Highschool DxD could be his power development. Writers might explore how he further hones his abilities, perhaps by training in new, secret locations. This could involve him facing off against powerful, previously unknown foes that push his limits and force him to unlock new levels of his power.
Another plot could involve the OC being sent by an unknown force to either help or hinder Lucifer. They initially seem like an enemy but as the story progresses, it's revealed that they are actually on the same side. They could team up to fight against a common threat to the devil world, like an ancient evil that is starting to rise again.
A lot of these fanfictions also deal with relationships. Lucifer's relationships with the other characters in the Highschool DxD universe, such as Issei or Rias, are explored. It could be a mentor - mentee relationship, a friendship, or even a more complex romantic relationship in some cases. And there's also the theme of mystery. Lucifer has a lot of secrets, and fanfictions often delve into uncovering those secrets and what they mean for the overall story.
Often, they feature Issei with enhanced powers due to his Lucifer connection. This can lead to more epic battles and power - up moments. The stories may also delve deeper into the lore of the devil world, exploring things that the original series only hinted at.
Yes, there are quite a few. You can find some on fanfiction.net. Just search for 'Highschool DxD Issei Lucifer' and you'll get a list of stories. Some of them might focus on Issei's growth as a devil with his Lucifer powers, while others could be about his relationships in a more in - depth way.
The cultural differences between Naruto's world and the Highschool DxD world would make it fascinating. Naruto comes from a world with ninja clans and a feudal - like society, while Highschool DxD has a more modern, yet supernatural, setting. When Godlike Naruto meets Lucifer, it would be like two different mythologies colliding. For example, Naruto's concept of honor and sacrifice might be completely new to Lucifer and his cohorts, and Lucifer's manipulative ways could be a shock to Naruto.
One idea could be that Naruto, with his godlike powers, somehow ends up in the world of Highschool DxD. He meets Lucifer and they initially have a clash due to misunderstandings. Naruto's power might surprise Lucifer and his followers. As the story progresses, they could find common ground and team up against a greater threat that endangers both Naruto's world and the Highschool DxD universe.