Naruto would be different in this fanfiction in many ways. Firstly, his appearance might change slightly to fit the more modern and different aesthetic of the Highschool DxD world. His clothing could be a mix of his ninja gear and the school uniform of Highschool DxD. His power would also have new applications. For example, his shadow clone jutsu could be used in creative ways in the battles and social situations in Highschool DxD. His character would grow as he learns about the new races and abilities in the Highschool DxD world, and he might start to see his own powers from a different perspective. He'd be more of a bridge between the two worlds, bringing his ninja values and adding them to the mix of the Highschool DxD universe.
Naruto would likely be more rebellious. In the original Naruto series, he was an outcast but still had a strong sense of justice. In this crossover, as a delinquent in the Highschool DxD world, he might question the existing power structures more. His sense of humor could also take on a more edgy tone.
Naruto's development could be centered around his ability to adapt to a new culture. The Highschool DxD world has its own set of rules, ethics, and social norms. He would need to learn and respect these while still maintaining his own identity. His sense of justice might also be challenged as he realizes that the good - bad divide in Highschool DxD isn't as clear - cut as in his own world. This could lead to him re - evaluating his beliefs and growing as a character.
If Kitsune Naruto was in Highschool DxD fanfiction, it could change the power balance. Naruto is already a very powerful character from his own series. His Kitsune powers, like the nine - tailed fox's chakra, are extremely potent. In Highschool DxD, this could make him a major player. He might not be as interested in the whole devil - angel - fallen angel conflict as the original characters, but his presence would force all the parties to take notice. His unique abilities would also mean that he could teach the other characters new ways of fighting or using their powers, which would have a big impact on the overall story.
Well, if Naruto had the Rinnegan in the Highschool DxD world, the power dynamics would change drastically. Naruto's abilities with the Rinnegan could make him a dominant force in the battles against the devils and other supernatural beings. He might introduce new jutsu styles that could shock everyone in the DxD universe. Maybe he'd use his Rinnegan to quickly analyze the powers of his opponents and come up with strategies on the fly.
Well, perhaps a plot where the Chimera concept from Highschool DxD is applied to Naruto characters. For example, some of Naruto's friends or foes start to develop Chimera - like abilities. And in the Highschool DxD part of the fanfiction, the characters there are intrigued by these new powers. They might try to study them or even use them for their own purposes. Naruto and his comrades would then have to deal with the interference from the Highschool DxD world while also figuring out what's happening to their own powers.
Naruto in this fanfiction would likely have a different sense of self - identity. He's used to being a ninja from Konoha, but now as the son of Amaterasu, he has a whole new heritage to grapple with. He might be more confident in his abilities, as he has this divine blood in him. Also, his relationships with others could change. For instance, he might be more cautious around devils, given his divine origin, but also be more curious about their ways compared to his original Naruto self.
A possible blend in the fanfiction could be through a magical or technological device. Maybe a scientist in Highschool DxD creates a device that can open portals to other universes, and Naruto's world is one of the destinations. When Naruto arrives, he discovers that there are elements related to Beelzebub there. The device could malfunction and start to merge the three universes in unexpected ways. This would force the characters to adapt to the new situation, with Naruto using his ninja training to survive, the Highschool DxD characters using their social and magical skills, and those related to Beelzebub using their demonic powers to deal with the chaos.
The female characters from Highschool DxD, like Rias, would be intrigued by the unique personalities of the Naruto characters. Rias might see potential in some of them to join her peerage. And the Naruto girls, like Sakura, would be a bit shocked at first by the more revealing outfits and flirty nature of some of the Highschool DxD characters. But over time, they would bond over things like protecting their friends and the school. The Naruto boys would respect the power of the Highschool DxD devils and might even try to incorporate some of their fighting strategies into their own ninja combat styles.
His character would develop in his relationships. Naruto is very friendly and outgoing. In Highschool DxD, he'd meet all kinds of characters. He could start off being a bit naive about the romantic and power - related relationships in the school. But as time goes on, he'd learn how to handle them better. For example, he might have to deal with the complex relationship between Issei and the various female characters. This would make him more mature in handling relationships and also more empathetic towards different situations.
Naruto would probably be very friendly and curious. He'd be excited to meet all the different types of beings in the Highschool DxD world. He might start by trying to make friends with Issei, sharing his stories about his own battles and adventures in his world.