Issei Exorcist DxD Fanfiction: What are some interesting plot ideas?

One idea could be an OC who is an exorcist with a special power to see the true forms of devils. They could start off as an enemy to the devils in the Highschool DxD world but then gradually form alliances due to a common threat. For example, a new, more powerful and evil force emerges that targets both exorcists and devils.

A plot could involve Issei and Koneko getting trapped in an alternate dimension. In this dimension, they have to find a way back home while also dealing with the strange creatures and rules there. This forces them to rely on each other more than ever and could spark a romantic relationship as they fight for survival.

They could go on a quest to find a lost artifact. This artifact could be related to the history of the holy swords. Issei's knowledge of the underworld and Xenovia's understanding of the church could be combined to track it down. Along the way, they might face challenges from both the underworld and the church who have their own interests in the artifact.

One interesting plot idea could be Issei and Yubelluna teaming up to face a powerful new enemy that neither of them can defeat alone. They have to combine their unique abilities and learn to trust each other during the battle.

One interesting plot idea could be that Kuroka and Issei have to team up to solve a mystery in the Underworld. Maybe there are strange disappearances of some low - level demons, and they suspect a powerful, hidden force is behind it. As they work together, their relationship deepens from just comrades to something more romantic.

A cool fanfiction could also focus on a love story between a character from Highschool DxD and an exorcist. How they deal with their different backgrounds, duties, and the potential disapproval from their respective groups would make for an engaging plot.

One idea could be that the OC has a unique power related to time manipulation. They could use this to prevent certain events that Issei was involved in, thus changing the whole dynamic of the story. For example, they might stop a particular devil attack before it starts, which would lead to different relationships forming between the various factions in the Highschool DxD universe.

One interesting plot idea could be Issei and Le Fay teaming up to face a new, powerful enemy that neither of their usual allies can handle. They could combine Issei's power of the Boosted Gear with Le Fay's magic in unique ways. Another could be a story where they accidentally end up in an alternate dimension and have to find their way back while also dealing with the strange rules and creatures there.

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.

One interesting plot idea could be Issei and Ophis going on a journey through different dimensions to find a way to strengthen their bond. Maybe they encounter various mythical creatures and have to overcome challenges together. Another could be a situation where they are forced to hide their relationship from the other characters in the Highschool DxD world, adding a bit of secrecy and drama.