Mabel is a top choice. She's always looking for love and adventure, so a love potion would fit right into her story. Wendy could also be interesting. She's cool and independent, and if a love potion made her fall for someone unexpected, it would be a great plot twist. Then there's Grunkle Stan. He's so gruff and practical, but if he were to be under the influence of a love potion, his interactions with the other characters would be hilarious. He might start acting all lovey - dovey towards the tourists or something.
Definitely Mabel. She's so full of love and enthusiasm already that a love potion would either enhance or muddle her emotions in really interesting ways. Dipper could also be great as he's more rational, and seeing him deal with the effects of a love potion would be a contrast to his usual logical self. And Bill Cipher would be an amazing addition. He could either use the love potion for his own devious plans or be the one to accidentally get affected by it in a really strange and unexpected way.
One idea could be that a character accidentally drinks the love potion and falls for the wrong person, like Dipper falling for Gideon, creating a chaotic and humorous situation. Another could be a character using the love potion to win a popularity contest in Gravity Falls, but things go awry when too many people fall for them at once. Maybe a character tries to use the love potion to make their crush notice them, but it backfires and makes the crush avoid them instead.
Syd is a character that can bring some humor to a fanfic. His interactions with Kat and his role in the story can be expanded. He could be involved in some comical misadventures while also being an important part of the group.
Dipper and Wendy are potential. Dipper's admiration for Wendy is obvious throughout the series. Another could be Mabel and some local character she meets. There's also a possibility for some of the minor characters like the old men who are always gossiping in the town to have some sort of love - related backstory or potential for a relationship within the Gravity Falls setting.
One of the great Gravity Falls fanfictions is 'Dipper's Strange Summer'. It delves deeper into Dipper's adventures and his relationship with the mysterious elements in Gravity Falls. Another good one is 'Mabel's Magical Misadventures' which focuses on Mabel's fun - filled yet sometimes chaotic experiences in the town. There's also 'The Mystery of the Hidden Falls' that explores new areas and secrets in Gravity Falls not shown in the original series.
Obviously Merlin himself could be affected. He's the one with the magic and might accidentally expose himself to the potion. Arthur is also a likely candidate. As the king, if he's affected by the love potion, it would have a huge impact on Camelot. Morgana could also be a character affected. If she were under the influence of a love potion, it could change her plans and her relationships with other characters. And Guinevere too, since she has important relationships in Camelot that could be altered by the potion.
Definitely Dipper and Mabel from both universes. Their different personalities in Reverse Falls and Gravity Falls make for really interesting interactions. Bill Cipher is also a popular choice. His chaotic nature can add a lot of drama, especially when he interacts with the characters from the other universe.
Mabel from Gravity Falls is also a popular character to pair. She could be paired with a character from Relativity Falls who has a different personality but shares her love for fun and creativity. Their interactions could lead to some really wacky and heartwarming scenarios, like planning a big party that combines the elements of both worlds.
I'm not entirely sure, but it probably features versions of Dipper, Mabel, and other main characters from Gravity Falls, just with different personalities or roles in this reverse version.
One possible love story in Gravity Falls could involve Mabel and a local boy. Mabel is this bubbly, creative girl. She might meet a boy who shares her love for arts and crafts. They could bond over making sweaters or creating some unique art pieces inspired by the strange creatures in Gravity Falls. They start spending more and more time together, going to the town fairs, and sharing their dreams. Their love story could be about two kind - hearted souls finding each other in this weird and wonderful town.
Dipper is a great choice. Their personalities are quite different, with Dipper being the curious and nerdy type and Pacifica being the rich and initially snobbish girl. Their interactions can lead to a lot of interesting storylines, like when they first met at the party and there was that instant tension.