One popular trope is the 'enemies to lovers' kind of story. Since they start off with some differences and mistrust, it's easy to build a story around them growing closer and falling in love. Another is the 'hurt/comfort' trope, where one of them gets injured or is in emotional distress and the other is there to support and heal them.
One popular trope could be the 'first time' trope. It might show their initial hesitation and then the passion that builds up as they make out. Another could be the 'interrupted make - out' where something or someone disturbs them at a crucial moment, adding some comical or tense elements to the story.
One popular trope is the 'enemies to lovers' arc. Since they might start off with some differences or even be on opposite sides initially, seeing their relationship develop from that is appealing. Another is the 'hurt/comfort' trope, where one of them gets injured or is in a tough situation and the other helps them out and their bond deepens.
One popular theme is their relationship growth. Fans love to explore how their bond deepens over time, from initial mistrust to a strong connection. For example, there might be fics that focus on how they support each other during difficult quests.
It could also be that the lack of such explicit content in the official story makes fans create their own versions. They want to see different sides of Rayla and Callum's relationship, and the 'lemon' fanfiction allows them to do that. Additionally, the creativity of the fanfic authors in developing these stories adds to their appeal.
One popular trope is the 'enemies to lovers' trope. The OC and Rayla could start off on the wrong foot, perhaps having different goals or misunderstandings. But as they are forced to work together, they begin to see the good in each other. Another is the 'fish out of water' trope, where the OC comes from a different background than Rayla, and has to adapt to her world, creating humorous and heartwarming situations along the way.
One interesting fanfiction could be about Callum and Rayla's adventures in a new, uncharted part of Xadia. They might discover a lost magic or a new species. Another could be a story where they have to overcome a big misunderstanding between them. For example, Rayla might misinterpret something Callum does in his pursuit of magic and they have to work through it.
You can start by looking on fanfiction platforms like Archive of Our Own (AO3). It has a vast collection of Rayla and Callum fanfictions. Just use the search function and type in their names. Another option is FanFiction.net, which also has a lot of works dedicated to them.
One idea could be a story where Rayla and Callum go on a secret mission deep into Xadia to find a long - lost magical artifact. They face many challenges along the way, and their relationship deepens as they rely on each other's skills. Another could be a fanfiction set in the future, where they have to deal with a new threat to the peace between humans and elves while also trying to start a family.
In many fanfics, Rayla and Callum's relationship is a central aspect. Writers may take their friendship to new levels, like delving deeper into their emotional connection. For example, a fanfic could show how they communicate their feelings more openly, which might not be as fully explored in the official story. This can add new dimensions to their characters.
One great 'Callum and Rayla fanfic' is 'The Journey Beyond'. It takes their relationship to a new level as they face an unknown magical threat together. The way the author describes their interactions and growth is really engaging.