Another theme might be power and politics. Given her background, fanfics could explore how she navigates the political landscape. She might be vying for power, or trying to protect her family's interests in a world full of political intrigue. There could also be themes of self - discovery, where she learns more about herself and her capabilities outside of what is expected of her in the original story.
I'm not sure of specific 'oc alys karstark fanfic' off the top of my head. But you could join relevant fan communities, like on Reddit or Tumblr. Fans there might be able to point you to some great ones. They often share and discuss their favorite fanfics.
There could be. A lot of fanfic writers are drawn to the Starks and the Karstarks in the world of Westeros. They might create interesting storylines where Oc Stark and Alys Karstark have adventures together, or perhaps a romantic relationship that develops against the backdrop of the political intrigue in the North. You might have to dig around a bit to find the really good ones, though.
One interesting storyline could be Rickard Stark's early years and how he built his power in the North. Maybe it shows his relationships with other northern houses and how he earned their loyalty.
Eddard Stark could be a great character to pair with Rickard Stark. As his son, their relationship can be explored in depth, like father - son training sessions or discussions about the future of the North.
One good example could be a story where the OC is a healer who comes to Winterfell. She catches Rickard Stark's attention with her kind and gentle nature. Their relationship develops as she tends to the sick and injured in the castle, and Rickard begins to rely on her not just for her healing skills but also for her advice. This type of fanfiction often explores how an outsider can impact the Stark family dynamic through a relationship with Rickard.
One common theme is loyalty. Given the importance of loyalty in the Stark and Karstark families, fanfics often explore how Oc Stark and Alys Karstark uphold or struggle with loyalty to their families and each other.
First, do your research on Rickard Stark. Know his character traits, his family values, and his role in the story's universe. Then, create a well - developed OC with a unique personality, backstory, and goals. For example, if your OC is a strong - willed woman, show how she clashes or meshes with Rickard's more traditional ways. Also, set the story in an interesting time period or situation, like during a war or a harsh winter. This will add drama and conflict to their relationship.
One possible plot could be that they marry for political reasons at first. Jon, being the Lord Commander or having some power in the North, and Alys, coming from the Karstark family, their union could strengthen the North's stability. As they get to know each other, they develop real feelings. They might face challenges from other noble families who are jealous or see their union as a threat. They then have to work together to overcome these political and social obstacles.
You can try some popular fanfiction websites like Archive of Our Own (AO3). There are likely to be various stories about this pairing there. Just use the search function and type in 'Jon Snow married Alys Karstark' and it should show relevant works.