Some crossovers might focus on the character relationships. A character like Percy could form an unlikely alliance with one of the devils in Highschool DxD. Maybe they team up to fight a common enemy that threatens both their worlds. Or perhaps a love interest could develop between a demigod and a character from Highschool DxD, which would be a really unique and complex relationship considering their different backgrounds and abilities.
One interesting crossover could be the combination of the demigod powers from Percy Jackson with the devilish abilities in Highschool DxD. For example, a character might use Percy's water - controlling powers in the middle of a battle in the Highschool DxD universe. Another could be the interaction between the different mythologies. In Percy Jackson, we have Greek mythology, and in Highschool DxD, there are elements of Judeo - Christian and other mythologies. A fanfiction could explore how characters from these different myth - based worlds react to each other.
One great crossover fanfiction could be where the characters from Highschool DxD end up in the world of Percy Jackson. For example, Issei could meet Percy and they'd have to team up against a common enemy. Maybe a Greek monster that has somehow made its way into the DxD universe. The clash of their different powers and personalities would make for an interesting story.
One interesting crossover could be the characters from Percy Jackson series ending up in the world of High School DxD. Maybe Percy could use his water powers in the battles that often occur in the DxD world. His skills as a demigod would surely give him an edge.
One interesting crossover could be Sasuke in the Highschool DxD world using his Sharingan abilities during Rating Games. His combat skills would add a new dynamic to the battles in the DxD universe.
One interesting crossover could be the characters from Naruto learning about the devil and angel society in Highschool DxD. For example, Naruto's ninjutsu skills could be a shock to the characters in Highschool DxD. He might use his shadow clone jutsu in a battle against a devil or an angel, which would completely change the dynamic of the fight. Another aspect could be the sharing of values. Naruto's strong belief in friendship and never - giving - up attitude could inspire some of the more self - centered characters in Highschool DxD.
A cool crossover could involve the power systems of both. Maybe Sasuke from Naruto tries to master some of the demonic powers in Highschool DxD. He might see it as a way to gain more strength, similar to how he sought power in the Naruto series. This could lead to some intense battles and power - up moments as he tries to combine his Sharingan abilities with newfound demonic powers.
In 'Persona 3 and Highschool DxD fanfiction', a cool crossover might involve the social links in Persona 3 being related to the relationships in Highschool DxD. For instance, the friendship between the characters in Persona 3 could be paralleled with the bonds of loyalty among the devils in Highschool DxD. Also, the Velvet Room in Persona 3 could have some sort of connection to the magic and power systems in Highschool DxD. It could be that the Velvet Room attendant has some knowledge about the devil fruits or the sacred gears in Highschool DxD.
A really fascinating aspect of crossovers in this type of fanfiction is the integration of storylines. Imagine the Akatsuki from Naruto getting involved in the power struggles in the Highschool DxD world. They could be after the Sacred Gears, thinking they are some kind of super - powerful ninja tools. This would completely disrupt the balance in the Highschool DxD universe and lead to all kinds of new plot developments as the characters from both series have to deal with this new threat.
One interesting crossover could be the characters from Highschool DxD using Ben's Omnitrix. Imagine Issei using the different alien forms to fight his battles in the DxD universe. It would add a whole new level of power and strategy.
Well, in some crossovers, the characters might team up for a common goal. Say, to fight against a new, powerful enemy that threatens both the Naruto world and the Highschool DxD world. The friendship between characters like Issei from DxD and Naruto could be explored. Issei's perverted nature could be played off against Naruto's more naive and pure - hearted personality, creating some comical situations. And there could be a sharing of knowledge. The scientific knowledge in the Highschool DxD world about things like Sacred Gears could be combined with the more traditional, spiritual knowledge in the Naruto world, leading to new inventions or power - ups.
Well, 'Percy Jackson and the Devils of Kuoh Academy' is also a great one. In this fanfiction, Percy finds himself in the Highschool DxD setting. The story plays around with how Percy's Greek mythology - based powers interact with the devilish and angelic beings in that world. It has some really exciting fight scenes and character interactions.