Well, if Bill Cipher kidnaps Fanfiction, it would be a really strange situation. Maybe he wants to distort the plots and the emotions that the fanfiction contains. He could turn happy endings into tragedies or vice versa. He might also use it to mess with the fans who love those fanfictions, causing them to be really confused and frustrated.
If Bill Cipher kidnaps Fanfiction, it could lead to chaos in the fictional worlds related to the fanfiction. Bill Cipher is known for his chaotic and unpredictable nature. He might manipulate the stories within the fanfiction, change the characters' fates in wild ways, or use the fanfiction as a tool to gain more power in the multiverse of fictional realms.
One possible plot could be that Bill takes Mabel to his dimension. There, Mabel has to use her wits and creativity to outsmart Bill. Maybe she befriends some of the strange creatures in Bill's realm who help her in her escape plan.
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.
It could lead to total chaos and a complete upheaval of the fictional world. Bill Cipher's victory might mean the end of all order and the rise of his malevolent rule.
Mabel could escape by using her grappling hook. She always has it with her and could use it to swing away from Bill when he's not looking.
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.
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.
The characters in Fanfiction could use their unique traits and abilities to escape Bill Cipher. For example, if there are characters with magical powers, they could combine their powers to break free from Bill Cipher's grasp. Or if there are intelligent characters, they might be able to outwit him by coming up with clever plans.
In a 'Naruto is Bill Cipher' fanfic, the story could start with some sort of interdimensional event. Naruto could be accidentally transported to the Gravity Falls universe where he somehow merges with Bill Cipher. When he returns to his own world, he has Bill Cipher's abilities but also some of his personality traits. This would lead to a lot of confusion among his comrades. The fanfic could then focus on Naruto's internal struggle between his original self and the influence of Bill Cipher. He might have to learn to control these new powers without losing his sense of self and also deal with the reactions of his friends and enemies in the ninja world who are both frightened and intrigued by this new Naruto.
Well, in some fanfictions, Bill might kidnap Will to gain more power. Maybe Will has some special ability or knowledge that Bill wants to use for his own evil plans.
Fanfiction often takes existing characters and puts them in new and unexpected situations. For 'abused bill cipher fanfiction', it might be a creative exploration of what would happen if Bill Cipher, who is usually depicted as a rather menacing and powerful entity, was made vulnerable through abuse. It could involve other characters from the original source either causing or reacting to this abuse, and might also delve into the consequences and potential for redemption or revenge within the fictional world.