Most BSD light novels often have complex characters. Since they are based on literary figures, they bring in the depth and complexity of those original personas. For example, a character might have the same traits as a famous writer but with a unique twist for the BSD universe.
Often, in Himiko x Kokichi fanfiction, the setting plays a crucial role. If it's set within the context of their original world, the power dynamics and the overarching plot of that world can influence their relationship. Maybe they team up to face a common enemy, and during this process, their feelings for each other gradually develop. Their interactions can be filled with banter, like Kokichi teasing Himiko about her spells not always working as expected.
In 'kokichi snaps fanfiction', it may also be related to the overall theme of the original work where Kokichi is from. If it's from a game, perhaps the events in the game lead him to a point where he can no longer hold back his true self or emotions. The fanfiction could be a way for the author to expand on that moment and show how it impacts the surrounding characters and the story world.
The appeal of all BSD novels lies in their ability to create immersive worlds. They draw readers in with their unique concepts and engaging storylines. For instance, the way they handle character relationships is very captivating. The conflicts and reconciliations between characters make for a great read.