Fanfiction.net is also a good place. There are many Gravity Falls fanfics there. However, the quality can vary more than on AO3. But if you search specifically for Mabel x Pacifica, you're likely to find some interesting reads.
One common theme is friendship development. They start off not getting along and then become close. Another is self - discovery. As they interact, both Mabel and Pacifica learn more about themselves. For instance, Pacifica might realize she doesn't have to be so uptight all the time.
One great fanfic could be 'The Bond Beyond Differences' where Mabel and Pacifica start off as rivals but gradually discover their shared interests and form a deep friendship that might turn into something more. It has really well - written character interactions.
In a good Pacifica x Mabel fanfiction, the writer should respect the source material. They can't just completely change the characters' personalities. It should also explore the unique dynamic between the two. Since Pacifica comes from a wealthy family and Mabel is more of a free - spirited, creative type, there are a lot of interesting scenarios that can be created from their interactions. The fanfiction could also introduce new elements that complement the Gravity Falls universe, like new creatures or locations that tie into their relationship.
You can start by looking on fanfiction platforms like Archive of Our Own (AO3). There are often tags related to 'Gravity Falls', 'Pacifica' and 'Mabel' that can help you narrow down the search. Some writers might also post their works on Tumblr, where you can search for Gravity Falls fanfiction blogs.
In Gravity Falls fanfiction centered around Mabel and Pacifica, the stories can take many directions. One common theme is the idea of growth for both characters through their relationship. Pacifica may learn to be more down - to - earth from Mabel, and Mabel might gain a bit of sophistication from Pacifica. Their friendship or more - than - friendship (depending on the fic) can also be a way to show different aspects of the Gravity Falls universe, like the social hierarchy in the town. And of course, there are always the cute moments where they share secrets or just have a good laugh together.
One common theme is the exploration of the 'opposites attract' concept. Bill is this powerful, otherworldly and often malevolent being, while Mabel is a sweet, innocent and positive girl. Their interactions based on these contrasting natures are often explored. Another theme is the idea of the unexpected. Their relationship is not something that one would expect in the normal Gravity Falls storyline, so fics often play with this element of surprise.
Pacifica could go from being a snobbish character to a more empathetic and loving one. Her relationship with Mabel could make her see the value in different kinds of people and experiences. For Mabel, she might become more confident in her own feelings and relationships, learning that it's okay to be different.
One possible plotline could be that they initially keep their relationship a secret from everyone in Gravity Falls. Mabel might be worried about how Dipper will react, while Pacifica is concerned about her family's image. But as they spend more time together, they realize they don't care what others think and decide to be open about their feelings.
Common themes in 'mabel x pacifica fanfic' include acceptance. They come from different backgrounds and have different personalities, so accepting each other for who they are is crucial. Also, there's the theme of breaking stereotypes. Pacifica is often seen as the snobby rich girl and Mabel as the free - spirited oddball. The fanfics usually break these initial impressions. And of course, the theme of female friendship is strong. It shows how two girls can support and care for each other in different situations.