Another great OC could be a Stark - like character who is not actually related by blood but was adopted into the family. They might have a strong sense of loyalty to the Starks and be involved in the political intrigues of the North. They could be a key player in battles, using their own unique battle tactics that they brought from their previous life before being adopted.
Arya Stark is often very popular. Her badass assassin skills and her journey of self - discovery make her a great character for fanfiction. Writers can explore her adventures in different lands and her encounters with new characters. Another popular one is Sansa. Her transformation from a naive girl to a strong and politically astute woman offers a lot of room for fanfiction writers to play with. They can create scenarios where she outsmarts her enemies and further cements the Stark power.
Sansa Stark is popular too. Fanfictions might focus on her growth from a naive girl to a shrewd political player. They could also explore her relationships with other characters in new and different ways, such as her forming a closer bond with Arya earlier in the story than in the show.
Obviously, Arya and Sansa Stark are the most popular as they are the main Stark sisters. Fans often love to write about their relationship, how it evolves from being somewhat estranged to a strong bond.
An OC Stark might be more politically astute than the original characters. They could form different alliances, like making a deal with the Iron Bank that gives the North more financial power and influence. This would shift the power dynamics not only in the North but also across Westeros. The original plot of various houses vying for the Iron Throne would be affected as the North becomes a stronger and more independent force.
Sansa also plays a crucial role. She becomes very politically savvy in the original series, and in fanfiction where the Starks are smarter, she could use her intelligence to navigate the complex political landscape of Westeros even better. She might be able to outmaneuver Cersei and other power - hungry characters more easily.
There are fanfictions where Jon Stark travels back in time. In this scenario, he uses his knowledge of future events to change the course of history in Westeros. For example, he might prevent certain tragedies from happening to his family. He could also use his knowledge to outwit his enemies and gain more power and influence. It's a really cool concept that many fanfiction writers explore.
One interesting Rickon Stark fanfiction could be where he survives and returns to reclaim Winterfell in a more powerful way. He might have been trained by some secret group during his time away, and he comes back with new skills and knowledge.
Most likely, there will be the traditional Stark family members. Ned Stark's children like Arya, Sansa, Bran, and Rickon could play significant roles. They might be joined by other Starks who were not as prominent in the original series but are given more spotlight in this fanfiction.
One idea for a male OC in the Stark family could be a long - lost cousin. He could have been sent away as a child for some reason, perhaps due to a political intrigue within the family. He might be a skilled swordsman, trained in secret by an old knight who knew his true identity. His personality could be a mix of the traditional Stark honor and a bit of a roguish charm, which he developed during his time away from the family. This would make him an interesting addition to the Stark family dynamics in a fanfiction.
A female Stark OC could play the role of a peacemaker. For instance, if there are disputes between different Stark siblings or between the Starks and other houses. She could use her diplomatic skills, which she might have learned from observing her father. Her calming presence and ability to see different perspectives would help in resolving conflicts.