Itachi might be another interesting choice. Itachi has a lot of secrets and a strong will. Bill Cipher would have a hard time manipulating Itachi directly. Their interactions would be a battle of wits, with Itachi trying to protect the world from Bill's chaos and Bill trying to break Itachi's resolve.
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.
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.
Dipper would be a great character to pair a female Bill Cipher with. Their personalities are so different - Dipper's inquisitive and cautious nature against her more wild and unpredictable self. It could create some really interesting storylines. Mabel could also work well. Her positive and friendly attitude might be a contrast to the female Bill Cipher, leading to some fun and heart - warming interactions.
I think Bill Cipher would be the most interesting. His unpredictable nature and his ability to manipulate reality make him a really engaging character. He can create all sorts of strange situations and challenges for Dipper and Mabel.
In a fanfiction, Bill Cipher could be a hidden power that was sealed away long ago in the Naruto world. When accidentally released, he starts to reshape the world according to his own chaotic vision. Naruto, with his unwavering belief in his friends and the power of the Nine - Tails, would be the one to stand up against Bill and try to return the world to normal.
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.
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.
Typically, it's enthusiasts who create 'dragon bill cipher fanfiction'. These could be individuals who have a passion for creating fictional worlds. They might be inspired by other works in the fantasy or mystery genres. Maybe they were thinking about how dragons could interact with something like bills and a cipher, and then decided to put their ideas into a story. It could be someone who loves to write and wanted to explore this unique combination of elements in a fictional setting.
Well, Bill Cipher is certainly very powerful, but whether he's the absolute strongest is debatable. Different fictional universes have characters with unique and formidable abilities, making it hard to compare them directly.
One great Bill Cipher fanfiction is 'The Cipher's Game'. It has an interesting plot where Bill interacts with the main character in a dream - like world filled with strange and mind - bending challenges. The author does a wonderful job of capturing Bill's chaotic and mischievous nature.