A third theme could be self - discovery within the relationship. As they get married, both Bill and Mabel might learn more about themselves. Maybe Mabel discovers a more adventurous side of herself because of Bill, or Bill becomes more empathetic through his relationship with Mabel. This theme of personal growth within the context of a marriage - like relationship could be really interesting in the 'bill marries mabel fanfic'.
Another theme might be the challenges of a new relationship. In a 'bill marries mabel fanfic', they would face various challenges, like dealing with each other's families or friends. And this could be a major theme as they navigate through these difficulties together. For example, if Bill has a different social circle than Mabel, how do they handle the integration? Also, cultural differences if applicable in their fictional setting could be explored.
One possible theme could be betrayal. If Bill kills Mabel, it could be seen as a huge act of betrayal depending on their relationship in the original source material.
One common theme is friendship. Their relationship is often explored in depth, showing how they support each other through different situations.
Well, I don't have a particular 'bill marries mabel fanfic' at hand. However, you might find some by joining relevant fan communities. They often share and discuss such fanfics among themselves. For example, on some dedicated forums for the show or characters that Bill and Mabel belong to.
One common theme is adventure. Since Bill is often associated with strange and otherworldly things, many fanfics might involve Bill and Mabel going on wild adventures together.
One common theme could be the struggle between Mabel's normal self and the influence of Bill. It might show how she tries to break free from his possession.
One common theme is friendship. Since they are from different backgrounds in the original story, exploring how they become friends is a popular theme. For example, they might learn to understand and accept each other's differences.
Friendship is a very common theme. Bill and Mabel have a special bond, and fanfictions often explore how they support and care for each other.
One common theme is the exploration of the 'opposites attract' concept. Bill is this powerful, otherworldly and often malevolent being, while Mabel is a sweet, innocent and positive girl. Their interactions based on these contrasting natures are often explored. Another theme is the idea of the unexpected. Their relationship is not something that one would expect in the normal Gravity Falls storyline, so fics often play with this element of surprise.
One possible theme could be redemption, although this would be highly controversial given his crimes. Another could be exploring his early career before the scandals emerged. But overall, it's a very difficult area to consider themes for, as his actions are so serious.
A common theme is the power struggle. Since Bill is an all - powerful being and Mabel is just a girl, there's often a dynamic where Bill tries to use his power over Mabel, but she resists in her own unique way. Another theme is the exploration of the unknown. Bill represents the strange and otherworldly, and Mabel is curious, so they often embark on adventures that involve the unknown in these fanfics.