A really cool gohan highschool dxd fanfiction could revolve around Gohan being the mysterious new student who everyone is curious about. As the story progresses, he slowly reveals his true power and his connection to the Saiyan race. He could get involved in the various power struggles in the highschool between different factions, like the devils' peerage groups, while also trying to keep his identity a secret as much as possible.
In addition to Gohan and Issei, Rias could be a main character in this fanfiction. She is a powerful devil and a key figure in the Highschool DxD universe. Her relationship with Gohan could be complex, especially when it comes to power dynamics and her own goals for her peerage. She might be intrigued by Gohan's power and want to recruit him or at least form an alliance with him.
There are fanfictions where a dragon in the Highschool DxD universe forms an unexpected alliance. For example, a dragon might team up with the devils against a common enemy. This can lead to some really cool battle scenes and strategic planning within the story.
One interesting story could be about Kalawarner's growth in power. In some fanfictions, she discovers new abilities and uses them to protect her friends in the dangerous world of Highschool DxD. For example, she might develop a new form of magic that no one has seen before.
Since the 'adult fanfiction' part is inappropriate, focusing on the 'High School DxD' proper, one interesting aspect is the unique power system. The Boosted Gear is a really cool concept. It not only gives Issei power but also has its own personality in a way. And the battles between different devil factions based on this power system are quite engaging.
One interesting DMC Highschool DxD fanfiction could be about a crossover where Dante from DMC enrolls in the Highschool DxD world. He might bring his unique demon - slaying skills and devil - may - care attitude, causing all sorts of chaos and also helping out in battles against other demons in the Highschool DxD universe.
One interesting Sairaorg fanfiction could be about his training journey in more detail. It might show how he overcomes various challenges and hones his skills further. Maybe it focuses on his relationship with other characters during this intense training period.
In some highschool dxd phoenix fanfiction, it could be about a love story between a phoenix - like character and one of the main protagonists. The phoenix's unique nature, such as their long lifespan or their connection to fire, could create interesting plot twists in the relationship. For instance, the couple might have to deal with the fact that the phoenix character will outlive the other, leading to emotional and moral dilemmas.
In some of these fanfictions, there could be a focus on the mythology of Quetzalcoatl integrated into the Highschool DxD universe. This could lead to exciting tales where the characters have to face off against threats related to this ancient mythology while also dealing with the typical high - school drama and the battles that are characteristic of the DxD world. There might be new magical abilities or artifacts inspired by Quetzalcoatl that change the course of the story.
A great Rias fanfiction could focus on her relationships outside of the main group. Maybe she befriends a human who has no knowledge of the supernatural world. It would be interesting to see how she tries to protect this new friend while also hiding her true identity as a devil.
One interesting story could be where the main character discovers a mysterious watch that gives him unique powers within the Highschool DxD universe. This watch might allow him to control time in battles or gain insights into the hidden secrets of the different factions.