One potential antagonist could be Bill Cipher from Reverse Dipper's dimension. He might have different motives or be more powerful in that realm and see the meeting of the two Dippers as a threat to his plans.
Maybe there's a new character, a dark entity that exists in the spaces between their dimensions. This entity doesn't want the two Dippers to combine their knowledge and power, so it tries to keep them apart and cause chaos.
One idea could be that Reverse Dipper, coming from his alternate dimension, initially confuses the regular Dipper. Maybe they start by arguing about who is the'real' Dipper. Then, they could team up to solve a mystery that involves both their dimensions.
Bill Cipher would be an interesting character to involve. If he shows up, he could be even more manipulative towards Reverse Dipper and Mabel. His chaotic nature could create a lot of conflict and drama. Reverse Dipper might be more vulnerable to Bill's tricks or perhaps more resistant in some unexpected ways. And Mabel would have to use her wits and kindness to try to counter Bill's evil plans.
I'm not entirely sure what specific 'Will Cipher Times Reverse Dipper Fanfiction' refers to. It could be a very unique or niche concept within the Gravity Falls fanfiction realm. Maybe it's about some sort of time - reversing adventure involving Bill Cipher and Dipper? Without more context, it's hard to say for sure.
One idea could be that Reverse Dipper, who might have different characteristics in this reversed world, meets Mabel and they initially have a misunderstanding because of their different ways of thinking. Maybe Reverse Dipper is more cautious while Mabel is her usual exuberant self. They could go on an adventure where Mabel tries to teach Reverse Dipper how to have more fun and let loose.
One idea could be that Dipper and Pacifica team up to solve a mystery in Reverse Falls that's been plaguing the town. Maybe it has something to do with the strange occurrences that are unique to Reverse Falls. They start off as reluctant partners but gradually grow to trust and rely on each other.
One big challenge would be the social stigma. In the normal world of the story, such a situation is completely unheard of and would likely be met with shock and disgust from others.
Perhaps the fanfiction's plot is centered around a time - traveling experiment gone wrong. Bill Cipher seizes the opportunity when Dipper is involved in this experiment and uses his powers to reverse time in a strange and unpredictable way. Dipper then has to navigate through a world where time is out of order, and he has to face Bill Cipher at different points in time, trying to set things right and save the Gravity Falls world from a fate worse than death.
One common theme is the role reversal. Instead of the usual dynamic, Dipper and Pacifica have swapped certain personality traits or social positions. Another theme is the exploration of their relationship from a new angle. It could be a budding romance or a newfound friendship.
One common theme could be role - reversal in their personalities. For example, Dipper might be more carefree and Mabel more cautious. Another theme could be exploring a different kind of relationship dynamic between them, like a more romantic - friendship hybrid.
Yes, there are some great ones. You can start by looking on Archive of Our Own (AO3). There are various stories that explore the relationship between Dipper and Pacifica in the Reverse Falls setting. Some focus on their adventures together, while others delve into the development of their relationship from mutual suspicion to something more like friendship or even romance.