The main characters are obviously Alex and Kaiden. They are the focus of the fanfic and the story usually revolves around their relationship, whether it's a friendship, a partnership in some adventure, or something else.
In this Japanese ghost story, there might be a theme of cultural heritage. It could show how certain traditions and beliefs in Japanese culture are related to the existence of ghosts. Another theme could be the exploration of the unknown. Ghosts represent the unknown in many cultures, and 'Kaiden' could be about the characters' journey to understand and deal with this unknown entity, whether it's through fear, acceptance, or trying to get rid of it.
It's likely a collection of ghost stories. Usually, such works involve various spooky tales about ghosts, spirits, and the supernatural. It might include stories of haunted places, encounters with malevolent spirits, and the like.
Sadly, I don't know the creator of 'hyaku monogatari kaiden 100 ghost stories'. It might be a work that has evolved over time, with different elements added by different people. It could have started as oral traditions in some rural areas of Japan, and then as the stories became more popular, they were gathered together and named as such, but the exact originator remains a mystery.
Suzaku in DxD fanfictions is often depicted as a powerful and passionate being. It is associated with fire and is known for its fierce loyalty. Byakko, on the other hand, is usually portrayed as a noble and strong character, often representing the power of the wind. Genbu is seen as a steady and wise entity, related to earth and having great endurance. Seiryu is frequently shown as a mysterious and agile character, connected to water and having a calm yet powerful presence.
One possible aspect of Genbu Black Tortoise Goddess fanfiction could be exploring her origin story. Maybe she was born from a primordial chaos, and the fanfiction could detail how she emerged and what her first experiences were in the newly formed world.
Kaiden, as a Japanese ghost story, would probably have a unique cultural backdrop. Japanese ghost stories often draw from their rich history, folklore, and religious beliefs. In this story, there might be references to Shinto or Buddhist concepts. Maybe it has a yurei, a traditional Japanese ghost, which is often depicted as having long black hair and wearing a white kimono, and the plot could revolve around how people interact with this supernatural being.
One great Alex and Kaiden fanfic could be 'The Adventures of Alex and Kaiden'. It might have them going on an exciting journey together, facing challenges and growing closer as friends. Another could be 'Alex and Kaiden: A New Beginning' which could explore their first meeting and how their relationship started.
In a more complex take on the fanfiction, we could imagine a scenario where the Genbu Black Tortoise Goddess has to face a great threat to her domain. This could lead to an epic battle where she has to use all of her wisdom and power to overcome the adversary. We could describe in detail the battle strategies she employs and how she overcomes her own limitations.
One popular Suzaku Byakko Genbu Seiryu DxD fanfiction is 'The Four Guardians' Adventure'. It has an interesting plot where the four guardians play important roles in the DxD universe. They face various challenges and team up with the main characters in unique ways.