One common trope is the 'rival - turned - lover'. In Highschool DxD, there are often strong female characters who start off as rivals but then develop romantic feelings for each other in yuri fanfictions. Another trope is the 'forbidden love' aspect, considering the complex relationships and power dynamics in the original series. This adds an extra layer of tension and drama to the yuri relationships.
Often, there's the 'outsider - looking - in' trope. A character might be observing the yuri relationship from afar, either being jealous, supportive, or having their own unrequited feelings. This trope helps to show different perspectives within the story and can make the main yuri relationship seem even more special. It also gives an opportunity to introduce new conflicts and plotlines, as the outsider's actions can impact the relationship of the two female characters.
In Highschool DxD fanfiction, a common trope regarding Issei is his growth as a character. He often starts as a pervy and weak character but gradually becomes stronger and more noble. Another aspect is his relationships, like his complex interactions with the various female characters in the series.
One popular theme is the exploration of relationships between female characters. In Yuri Highschool DxD fanfiction, writers often focus on the emotional bonds and interactions between the female characters. Another theme could be the development of unique powers or abilities within the Yuri context of the story. For example, a character might discover a new power that is related to her relationships or her own self - discovery. Also, the theme of friendship and loyalty among the female characters is quite common. They support each other through various challenges in the high school setting, which is full of supernatural elements in the Highschool DxD universe.
The unique character of Rossweisse in the Highschool DxD universe is one factor. Her backstory and personality traits can be interestingly explored in a yuri context. For example, her role as a Valkyrie and her interactions with other female characters can be re - imagined in a romantic or friendly way that yuri fanfictions often do.
One popular trope is the 'Fish out of Water' scenario. For example, a character from Prototype suddenly finding themselves in the Highschool DxD world full of devils, angels, and other supernatural beings. It creates a lot of comical and interesting situations as they try to adapt.
One of the popular tropes in Persona fanfiction is 'alternate reality'. Writers like to explore what would happen if the events in the game took a different turn. In Highschool DxD, the 'rivalry' trope is common, especially between different devil clans. In a fanfiction that combines both, a trope could be 'culture shock'. A Persona character coming into the Highschool DxD world would experience a huge culture shock due to the different rules, species, and social structures. And also, the 'mentor - mentee' trope could be used. Maybe a powerful character from Persona becomes a mentor to a young devil in Highschool DxD, guiding them through their power - up journey.
One great Highschool DxD yuri harem fanfiction is 'Yuri in the Underworld'. It has an interesting plot where the female characters form unique relationships. The author does a good job of portraying the characters' personalities in this yuri - themed harem setting.
The popularity of Highschool DxD yuri harem fanfiction is due to the unique combination of elements. The Highschool DxD world already has a large and diverse cast of characters. When you add the yuri and harem aspects, it creates a lot of potential for different relationship dynamics. Fans are interested in seeing how the female characters interact in romantic or semi - romantic ways.
A less common but still interesting trope is the 'reversal of roles'. In some fanfictions, Issei might find himself in a world where his devil powers are seen as something different or even feared in a new way. Maybe in a world of pure angels, he is the outcast and has to prove himself not to be an evil entity. This trope allows for a lot of character exploration and development for Issei.
In Highschool DxD OC fanfiction, the 'Power - Up' trope is quite common. Your OC starts with a certain level of power and then, through training, battles, or special encounters, they gain more power and become stronger. The 'Redemption' trope can also be used. If your OC has made mistakes in the past or has a dark history, they can strive to redeem themselves throughout the story. Also, the 'Chosen One' trope works well. Your OC could be the one chosen to save the supernatural world from a great threat, like an impending war between devils, angels, and fallen angels. This gives them a sense of purpose and importance in the story.
The crossover element itself is a huge trope. Combining the unique worlds of Naruto, Highschool DxD, and the concept of ghouls allows for all kinds of interesting scenarios. Such as when the different magic systems and ninja techniques interact. For instance, a character might try to use a jutsu in the world of Highschool DxD or combine a devil's power with a ghoul's ability.