One interesting plot point could be that Naruto is sent to the High School DxD universe as a sort of test or punishment (the 'dark knight' angle could play into this). He has to navigate the complex social and power structures there. He might be mistaken for a new type of devil or some other supernatural being at first. As he tries to find his way back home, he gets involved in the ongoing conflicts between the different factions in High School DxD, like the devils, angels, and fallen angels, and uses his ninja techniques to turn the tides in various battles.
In this fanfiction, Naruto could form an unlikely alliance with some of the characters from High School DxD. He might team up with Issei, for instance. Naruto's chakra could be seen as a different form of power compared to the sacred gears in High School DxD. They could learn from each other's fighting styles and strategies. Also, the 'dark knight' aspect could mean that Naruto has some sort of secret mission or a past that he's trying to hide, which adds an element of mystery to the story.
Well, a possible story could be about Naruto ending up in the world of High School DxD. Maybe he could use his ninja skills in the battles there. For example, his shadow clone jutsu could be a really unique ability in the world of High School DxD where they mostly deal with magic and devil powers. And as a 'dark knight' in this fanfiction, he might have a darker, more brooding personality, perhaps influenced by the more mature themes in High School DxD.
A fanfiction might explore how the power of the Excalibur in High School DxD would interact with Naruto's chakra. Since the Excalibur is a powerful holy weapon, it could have some interesting reactions when in the presence of Naruto's unique chakra, which is different from the magic in the High School DxD world. For example, it could either enhance or nullify certain abilities depending on how the author writes it.
In a Naruto - High School DxD fanfiction, the power levels would be really interesting to explore. Naruto's sage mode and tailed - beast forms are extremely powerful. In the DxD world, there are different power systems like the Sacred Gears. It would be fascinating to see how Naruto's powers interact with the powers of the DxD characters. For example, could his Rasengan be enhanced by a Sacred Gear? Or how would he fare against a devil's magic?
One possible scenario could be that Naruto characters are somehow transported to the world of High School DxD. Naruto's ninjutsu skills would be quite a shock to the devils and angels in that world. For example, Sasuke's Sharingan could give him an edge in battles against the supernatural beings in High School DxD. And Naruto's never - give - up attitude might inspire some of the characters there to face their challenges more bravely.
One idea could be Naruto being summoned into the High School DxD world during a battle. His unique ninja skills would shock the devils and angels in that universe. He might form an unlikely alliance with Issei, perhaps teaching him some ninja techniques in return for learning about the Sacred Gears.
One idea could be that Naruto is somehow transported to the world of High School DxD. He could use his ninja skills, like shadow clones, in the battles that take place in the DxD universe. Maybe he'd form an alliance with Issei and his group, and teach them some ninja techniques to fight against the devils and fallen angels.
In a Naruto - High School DxD vampire fanfiction, the characters from both universes could have their powers combined in interesting ways. The devils in High School DxD might see Naruto as a strange new being with his chakra. And Naruto might be intrigued by the different power systems in High School DxD, like the Sacred Gears. The vampires in this crossover could also have unique interactions with Naruto, perhaps seeing his life - force as something different from what they're used to.
Another possibility is a story where the power - up systems of both Naruto and High School DxD are combined. For example, Naruto could learn about the Boosted Gear and use it in a new form of his Rasengan. Or Issei could gain chakra and learn some basic ninja techniques. This would create an interesting dynamic as they face common enemies.
One idea could be that Naruto is somehow transported to the world of High School DxD. He could use his ninja skills, like shadow clones, in the battles against the devils and fallen angels in that universe. Maybe he'd form an alliance with Issei and his group, teaching them some unique ninja techniques.
In a Naruto - High School DxD demigod fanfiction, Naruto could be seen as a demigod in the DxD universe due to his extraordinary powers. His chakra would be a completely new concept to the DxD characters. He could teach them about it and in return, learn about the different forms of power in the DxD world. For example, he might be intrigued by the power of Devils and Angels and how they interact. This could lead to some interesting battles and power - up moments for both Naruto and the DxD characters.
He could introduce new combat styles. His speed and agility from being a ninja would be a huge advantage. The characters in High School DxD might be very intrigued by his ability to move so quickly and perform complex jutsus.