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.
One common theme is the clash of different power systems. Bill Cipher has his otherworldly and chaotic powers, while the Naruto characters have chakra - based abilities. So, the fanfictions often revolve around how these two power systems interact.
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, it could be a really interesting creative crossover. Bill Cipher from Gravity Falls is this super powerful and chaotic being. In a Naruto fanfic, he could bring a whole new level of chaos to the Naruto universe. Maybe he'd be a new kind of enemy that the ninja have to face, one that doesn't play by the normal rules of chakra and jutsu. It could also be a chance for some really cool character interactions, like how would Naruto react to Bill's mind - games and illusions.
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.
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.
He could be a mysterious outsider. Just suddenly appear in the Naruto world and start causing trouble. Maybe he's looking for something in the Naruto universe, like a powerful chakra source or a special jutsu. And the ninja have to figure out who he is and what he wants before he destroys everything.
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.
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.