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.
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 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.
Yes, there are quite a few. You can start by looking on popular fanfiction websites like Archive of Our Own. Just search for 'Jon Snow married Val' and you'll find a variety of stories, each with their own take on how their relationship could develop into a marriage and what that would mean in the context of the 'Game of Thrones' universe.
The main characters are obviously Jon Snow and Ygritte. Jon Snow is a member of the Night's Watch who has a complex background. Ygritte is a wildling woman. Their relationship is central to the fanfiction as they are the ones who get married.
One possible plot could be that Jon, after becoming King in the North, realizes that a marriage to Val would be a great way to secure peace with the wildlings. So he marries her, and they face many challenges together as they try to integrate the wildlings into the North's society.
Yes, there are. There are many fanfictions that explore the idea of Jon Snow getting married. Some might pair him with characters from the 'Game of Thrones' universe like Daenerys, Arya (in very different interpretations), or even new original characters created by the fanfiction authors. These stories often take different routes from the original plot and can be really exciting to read.