The main difference is the form. In the original, Bill Cipher is his non - human, otherworldly self. But in fanfic, as a human, his physical limitations and advantages are different. He might not have the same instant, all - powerful abilities.
Create an interesting plot. Maybe set it in a new dimension where Bill has different powers or limitations. You could also introduce new characters that interact with Bill in unique ways. For instance, a character who can see through his lies and challenges him directly. This would add more depth and conflict to the story.
First, give the character a strong motivation. For example, if the character is a scientist, their motivation could be to study Bill Cipher's otherworldly powers. This will drive their actions and reactions when interacting with him. Also, give them flaws. Maybe they're overly curious which sometimes gets them into trouble when dealing with Bill.
Will might find a way to escape on his own. Since he is also a Cipher, he could have some hidden powers or tricks up his sleeve. Maybe he manages to outwit Bill and gets away, which then sets up a cat - and - mouse chase between them throughout the fanfiction world. The story could also take a darker turn. Bill might start to torture or manipulate Will, changing Will's personality or making him do things against his will. This could lead to a conflicted Will, and the other characters might have to deal with this new, changed Will when they finally find him.
I'm not entirely sure specifically what that fanfiction is about. It could potentially be about Bill Cipher achieving or obtaining Will Cipher in some way, perhaps in a strange or otherworldly scenario within the context of the Gravity Falls universe. It might involve some sort of power play or a very unique plot device that only fans who have read it would know for sure.
I think Kakashi would also be a great character to pair with Bill Cipher. Kakashi is very intelligent and experienced. His encounter with Bill Cipher would be full of mind - games as he tries to figure out Bill's motives and powers while also protecting the village from Bill's chaos.
Dipper Pines could be one of the main characters. He might be the one who first discovers Bill's transformation and tries to figure out if it's a trick or if Bill is truly changing. His inquisitive nature would make him a great foil to Bill's new human self.
One idea could be Bill Cipher getting trapped in a human form and having to navigate the strange world of human emotions and social norms. It would be a comical yet thought - provoking plot as he tries to understand things like friendship and love while still having his devious nature.
The Bill Cipher triangle in fanfic often represents mystery and power. It can be a central symbol around which the plot revolves. Maybe it's a portal to another dimension or holds some dark secrets that the characters are trying to uncover.
In Bill Cipher fanfic, the concept of 'hurt' is crucial. It can be physical, mental or emotional hurt. By showing characters being hurt by Bill, it emphasizes his power and the threat he poses. It also allows for character development as the hurt characters might grow stronger or more broken. This can lead to interesting relationship dynamics among the characters, like some might become more united against Bill, while others could be paralyzed by fear due to the hurt they've endured.