In this fanfiction, Naruto might initially struggle to control Pantera's power. Since he's used to his own chakra-based abilities in his own world. But as he gets to know more about Pantera in the DxD setting, he could start to master it. He might team up with some of the characters from DxD, like Issei, and they could go on adventures together, using Naruto's new - found power of Pantera to defeat common enemies.
One possible plot could be that Naruto is mistaken for a threat when he first arrives in the DxD universe with Pantera. He then has to prove that he means no harm. As he wields Pantera, he might attract the attention of powerful beings in the DxD world. He uses his experience from his own world, like his training with Jiraiya, to figure out how to best use Pantera's powers in different situations, whether it's in a fight or just to show off his new abilities to gain the trust of the DxD characters.
Well, perhaps in the fanfic, the Gunbai is actually a key to a different dimension. Naruto, while wielding it, accidentally opens this dimension and has to face new and strange enemies. He then has to figure out how to use the Gunbai not just as a weapon but also as a tool to close this dimension before it's too late.
One possible plot could be Naruto's unique abilities from the Naruto world being introduced into the Highschool DxD universe. For example, his shadow clone jutsu could be used in some creative ways during battles or school events. Maybe he uses it to attend multiple classes at once and ends up getting into comical situations.
The plot could involve Naruto arriving in the DxD world with his goal - seeking nature intact. He realizes that the power dynamics here are very different from his own world. He starts to learn about the different races and their powers. As he is seen as a god, he is constantly challenged by various powerful beings. He uses his wisdom from the ninja world and his growing understanding of DxD to resolve conflicts and perhaps find a way back home while also making a positive impact on the DxD world.
One possible plot could be Naruto being transported to the Dragon DxD world. He might start as an unknown entity and have to prove himself. His ninja skills could be mistaken for some new form of magic. He could then form alliances with some of the characters in the DxD world, like Issei and his group, and together they could face common enemies.
Naruto's confidence would probably grow even more. He already has a strong sense of self - belief from his experiences in his own world. But with Pantera in DxD, he'd be facing new and powerful foes. Every victory with Pantera's power would boost his confidence. He might also become more strategic as he combines his ninja strategies with the abilities of Pantera. He'd need to think about how to use Pantera's powers in the most effective way in battles against DxD's unique creatures.
One possible plot could be that Godlike Naruto, with his incredible powers, enters the world of Highschool DxD. He meets Ophis and they form an unlikely alliance. Naruto's sense of justice might lead him to deal with the various power struggles in the DxD world, while Ophis, with her unique abilities, could provide support. Maybe they team up to face a common enemy that threatens both their interests.
One possible plot could be that Rikudou Sennin somehow gets transported to the world of Highschool DxD. Maybe his powers disrupt the balance there. For example, his chakra could be mistaken for some kind of new and strange power in the DxD world. The characters in DxD might initially be wary of him but then start to see the potential of his abilities and try to recruit him for their own purposes.
Well, in this fanfiction, Naruto's origin as the son of Amaterasu could lead to a story where he is initially shunned by some in the DxD world because of his strange powers. But as he proves himself in battles and shows his kind heart, he starts to gain allies. His journey could also be about uncovering the secrets of his mother Amaterasu and how that relates to the overall balance of power in the DxD universe. Maybe he has to face an ancient evil that only his combined ninja and divine powers can defeat.
One possible plot could be Naruto being summoned to the DxD world by some sort of magical accident. He could then use his ninja skills, like his shadow clone jutsu, in unique ways to combat the devils and exorcise evil spirits. For example, his clones could be used to surround and confuse enemies during an exorcism battle.
In a fanfiction where Naruto goes to Highschool DxD, he could introduce new concepts of chakra to the world. This would be really fascinating as the characters in DxD might try to incorporate it into their own powers. Naruto could also be a bit of a fish out of water, not fully understanding the social norms and hierarchies in Highschool DxD at first. But his kind heart would help him navigate through it all, and he'd end up changing the school environment in a positive way with his unique personality.