Maybe she gets jealous easily in the fanfic. If there are new female students or devils around Issei, she acts like a spoiled child. She could use her influence to try and keep them away from Issei, causing all sorts of misunderstandings and chaos. For example, she might spread false rumors about the other girls or create difficult situations for them at school.
One plot could be that Rias tries to control all the events in the school's Rating Game without considering her teammates' opinions, just because she thinks she knows best as a spoiled brat. She might ignore their strategies and force her own, leading to problems in the team.
Another possible plot is that Rias demands special treatment from the school faculty. Since she is a spoiled brat in this fanfic, she expects to have privileges that other students don't. She could throw fits if she doesn't get her way, like trying to get better living quarters or more resources for her club, regardless of how it affects the school's balance and fairness.
Well, in some fanfictions that depict Rias as a spoiled brat, they might show her using her status and power to get what she wants in the Highschool DxD universe. For example, she could be overly demanding with her peerage members.
One possible plotline could be that Naruto is transported to the Highschool DxD world and immediately notices Rias's overbearing attitude. He decides to oppose her and starts to gather allies among the other students and characters who are also fed up with her ways. As a result, a power struggle ensues between Naruto and Rias.
One great fanfiction idea could be that Issei discovers a new power within himself that is directly linked to Rias's heritage. Maybe he can tap into an ancient magic that only works in harmony with Rias's own powers. As they train together to master this new ability, their relationship deepens beyond just the typical master - servant bond in the Highschool DxD world.
A common theme is power - up. Rias may gain new powers or improve her existing ones. This could be related to her devil heritage or through some special training or encounter.
In 'Highschool DxD' fanfiction about Rias, her character often retains her strong - willed and noble nature. She is a powerful devil, and in fanfictions, her leadership skills and loyalty to her friends are usually emphasized.
One possible fanfiction could be about Rias and Sona teaming up for a school event. They might put aside their usual competitiveness and work together to organize a devil - related festival at the school. They could combine their unique skills and powers to create an amazing event that not only impresses the other students but also strengthens their bond as friends.
Another reason might be a clash of values. Issei could have a very different view on how to handle certain situations compared to Rias. For instance, he might believe in a more direct and aggressive approach while Rias prefers a more diplomatic or strategic one, and this constant difference in opinions could lead to his hatred over time.
One possible plot could be how the Occult Research Club copes with Issei's death. They might struggle to move forward while also trying to figure out who was behind his death. Maybe they suspect a powerful enemy from the Underworld or a rogue devil. Another idea could be that Issei's death sets off a chain of events that leads to a new power struggle in the supernatural world, as different factions vie for the power he once held or the influence he had over certain areas. And his friends could be visited by his spirit in dreams, guiding them to uncover secrets he didn't have time to reveal before his death.
In Highschool DxD fanfiction, male Rias often has a different leadership style. For example, he might be more aggressive or direct compared to the female Rias. His relationships with his peerage can also be distinct. He may form brotherly bonds with male members rather than the more complex relationships the female Rias has.
Power - up themes are also quite common. Issei often gets new powers or abilities, and Rias may play a role in that. For example, in some fanfictions, Rias helps Issei to master a new form of his Sacred Gear. This not only strengthens Issei but also deepens their bond as they train together. Another aspect is the exploration of the supernatural world in the context of their relationship. Since Highschool DxD has a rich supernatural setting, fanfictions may expand on this, like how Issei and Rias face new threats from the underworld or other dimensions together, which further cements their relationship and showcases their individual growth.