Highschool DxD x OC Sitri Fanfiction: What are some interesting plot ideas?

Start with giving the OC Sitri a distinct personality trait. For example, if they are extremely curious, it can drive their actions and decisions. They could be constantly exploring the world of Highschool DxD and getting into all sorts of situations because of their curiosity.

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.

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.

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 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.

A cool plot might involve the Si Sitri character forming an unexpected alliance with other factions in the Highschool DxD universe. This could lead to all sorts of adventures and challenges as they try to keep the alliance together and achieve their common goals. For example, they might team up with the Gremory group to face a common enemy that threatens both of their interests.

The OC could be a new transfer student with a mysterious past. As the story progresses, it's revealed that they are on a quest to find a powerful artifact that is somehow connected to the characters in the harem. This could lead to adventures together, and the building of deeper relationships within the harem.

One idea could be an OC who discovers an ancient and forgotten form of Excalibur. This could lead to a power struggle among the various factions in the Highschool DxD universe as they all vie for control of this newfound power. The OC would have to navigate through political intrigue and dangerous battles to keep the Excalibur safe.