Highschool DxD Male OC x Rias: What Are Some Interesting Plot Ideas for Their Relationship in Fanfiction?

One idea could be that the OC has a unique power that helps Rias and her harem in unexpected ways. For example, the OC might be able to sense danger before it arrives, allowing them to better prepare for battles against other factions. Another plot could involve the OC having a past connection to one of the members of Rias' harem, which creates some drama and tension as they navigate their new relationships within the harem. Maybe the OC is a long - lost relative or an old friend who has changed a great deal.

One idea could be an OC who is a transfer student with a unique power that no one in the Highschool DxD universe has seen before. This power could attract the attention of the main characters and lead to various adventures and alliances.

One idea could be a story where Rias and Riser are forced to team up against a common enemy that threatens both of their peerages. This would put them in a situation where they have to set aside their differences and learn to work together. As they do so, they gradually start to understand each other better and a newfound respect develops between them.

One idea could be an OC male who is a transfer student with a unique power, like the ability to manipulate shadows. He could use this power to protect his friends in the dangerous world of Highschool DxD.

Maybe the OC is an artist who can create magical art. Akeno is fascinated by this art and the emotions it evokes. They could start collaborating on projects that are not only artistic but also have a deeper meaning in the context of the Highschool DxD universe. For instance, creating art that can temporarily shield them from attacks or art that can influence the minds of their enemies. Their relationship could grow as they explore the potential of the OC's art together.

Maybe the OC Sitri is from a different branch of the Sitri family that has been in hiding. Their appearance in the story could stir up old rivalries or create new alliances. They could bring with them ancient knowledge or artifacts that change the power dynamics in the Highschool DxD world.

One idea could be the OC having a unique power that attracts the various characters in the harem. For example, if the OC can manipulate time in a certain way, it could lead to some really interesting situations. Maybe they use this power to save a member of the harem from a dangerous situation, which then makes that character develop strong feelings for the OC. Another plot idea is the OC being from a different dimension and having to adapt to the Highschool DxD world while building relationships with the harem members.

One plot idea could be that the OC is a new transfer student at the school and has a special power that Koneko is initially suspicious of. As they are paired up for a school project, they start to understand each other better. The OC could be from a different supernatural group, and through their interactions, they help bridge the gap between their respective groups in the Highschool DxD universe.

One idea could be that the OC is a new student at the school and immediately catches Akeno's eye. They start off as friends but slowly develop deeper feelings as they go through various supernatural battles together. Another plot could involve the OC having a special power that Akeno is intrigued by, and they bond over exploring and controlling that power.

One idea could be a story where Issei and Rias have to face a new, powerful enemy that targets their relationship. Maybe an ancient demon who sees their bond as a threat to the traditional demon hierarchy. Another plot could be a time - travel story where they go back in time and have to deal with past events that could change their present relationship. For example, they might have to stop an event that would have otherwise led to their separation.