What are some interesting plot ideas for Itachi Highschool DxD crossover fanfiction?

One idea could be that Inuyasha gets transported to the world of Highschool DxD. He might mistake the devils and angels there for demons from his own world and start attacking them. This would create chaos and also lead to some interesting alliances as the characters from Highschool DxD try to figure out who he is and why he's there. Another plot could involve a shared enemy. Maybe a powerful demon from Inuyasha's world somehow makes its way to the Highschool DxD universe and starts causing trouble for both groups. They would then have to combine their powers and knowledge to defeat it.

One interesting plot could be the characters from Highschool DxD somehow ending up in the Bleach universe. Maybe Issei and his friends are mistaken for Hollows due to their demonic energy and are hunted by Soul Reapers. They then have to prove their innocence while also learning about the complex spiritual world of Bleach.

One idea could be to have the characters from High School DxD cross over into a world ruled by different gods. They could be tasked with a quest to restore balance. For example, Issei could use his Boosted Gear in a realm where the gods' powers are waning and his power might be the key to saving the day.

A cool plot idea could be a tournament where characters from both Highschool DxD and Naruto participate. The ninjas would show off their jutsu and the devils would display their powers. Also, imagine if Naruto got a Sacred Gear. He could use it to enhance his Rasengan or even create a new jutsu that combines his ninja abilities with the power of the Sacred Gear. Or perhaps, the female characters from Highschool DxD like Rias could teach some of the kunoichi in Naruto about different ways of using their femininity as a power, which could lead to some interesting character development for the kunoichi.

Another plot could involve the Quincy from Bleach. Uryu could be mistaken for a Devil by some of the Highschool DxD characters because of his unique powers. This misunderstanding could lead to a conflict at first, but then they realize they are all on the same side against a greater threat, like a powerful fallen angel who is trying to start a war between the Hollows, Devils and Quincies.

Maybe the dragons from Fairy Tail are related to the dragons in Highschool DxD in some ancient way. So, characters like Igneel might have a connection to the dragon in DxD. This could lead to a search for the truth about their origins and a fight against a common enemy that threatens both worlds.

One idea could be that Naruto characters attend the Highschool DxD academy. For example, Naruto himself could be a new student with his unique ninja skills. He might form an unlikely friendship with Issei. Another idea is a battle tournament where ninja techniques are pitted against the devilish powers in the DxD world.

One idea could be to cross it with a magical girl anime. The main character from Highschool DxD could find himself in a world full of magical girls and form a harem with them. They could fight together against common enemies while also dealing with the typical harem situations like jealousy and misunderstandings.

One idea could be that Naruto characters attend the Highschool DxD school. Naruto could use his shadow clone jutsu to cause all kinds of chaos during classes or P.E. Another is that some of the Highschool DxD devils could be interested in Naruto's chakra and try to make a deal with him. Also, the ninjas from Naruto could introduce their unique fighting styles to the students at Highschool DxD, leading to some epic battles in the schoolyard.

One idea could be the exorcists from D Gray - Man ending up in the world of Highschool DxD. They might initially be mistaken for devils or angels due to their strange powers. For example, Allen Walker's cursed eye could be seen as a very unique and perhaps threatening power. Another plot idea could involve the search for the Innocence in the Highschool DxD world. Since both worlds have different forms of power sources, it would be interesting to see how the Innocence interacts with the Sacred Gears. Maybe a character with a Sacred Gear could also be a potential host for the Innocence, creating a whole new dynamic.