If Robb Stark married a Frey in fanfiction, it would likely have a huge impact on the plot. It could lead to different political outcomes, affect the relationships among characters, and even rewrite the course of the entire saga.
It could lead to a major shift in the power dynamics of the story. Maybe it would prevent the Red Wedding or cause other unforeseen conflicts.
One possible plot could be that after the marriage, Robb Stark has to deal with the complex Frey politics. He might try to use the union to strengthen his position in the North. Maybe he and his Frey bride gradually fall in love despite the initial political motives of the marriage.
If Robb Stark married a Frey girl, it might have led to a more stable alliance between the Starks and the Freys. This could have affected the power dynamics in the story and altered the outcome of the war.
It could change it a great deal. In the original story, Robb's actions regarding the Freys led to the Red Wedding. But if he married a Frey, it would mean no Red Wedding. This would keep Robb alive and his army intact. It could also change the power dynamics in Westeros as the Stark - Frey alliance would be very strong.
One consequence could be a shift in the power balance. The Mountain was a powerful fighter in service of certain lords. His death would leave a power vacuum among his allies. Robb Stark, on the other hand, would gain more notoriety. His reputation as a fearsome and capable leader would spread, making his enemies more cautious of him.
The Old Gods themselves would be crucial. They could be represented in various forms like the weirwood trees. And there might be some sort of priest or seer who serves as an intermediary between Robb and the Old Gods, guiding him through the spiritual experiences.
Well, in the fanfiction world, Robb Stark might also get some unexpected help. Maybe there are some magical elements involved. A wizard or a sorceress could weaken the Mountain's strength or defenses. This would give Robb an edge in the fight. Then, with his courage and fighting skills, he could step in and slay the Mountain.
A sense of adventure is also present. They were in the middle of a war - torn Westeros. Fanfictions might take them on different adventures together, away from the main battles, or they could be involved in secret missions that test their relationship. Also, the theme of loyalty, both to each other and to their respective causes, is explored. How they balance their loyalty to each other with their loyalty to their families and kingdoms is a rich area for fanfiction writers.
A prevalent theme in Robb Stark time travel fanfiction is the alteration of history. Robb, with his knowledge from the future or past, depending on the direction of his time travel, attempts to change the course of events in Westeros. This often involves political intrigue as he has to navigate the complex power dynamics all over again. Also, self - discovery is a theme. As he experiences different timelines, he learns more about himself and his capabilities. For example, in some fanfics, he realizes that his leadership skills can be applied in different ways than he originally thought.
One great 'Robb Stark OC fanfiction' is 'The North's New Hope'. It has an original character who becomes an important ally to Robb. The story is full of political intrigue and battles, just like in the original 'Game of Thrones' setting.
One possible ending is that Robb Stark becomes a great and respected king, ruling over a prosperous North. Another could be that he steps down after achieving victory and hands over the power to someone he trusts, perhaps to live a more peaceful life.