In a fanfic where Robb wins the war, the Stark family's reputation would be greatly enhanced. Robb would be seen as a great leader. He might also start to reform the feudal system in Westeros. For instance, he could give more power to the smallfolk, which would be a revolutionary change. This could lead to a more democratic - like system in the long run. He would also have to deal with the remaining enemies who might be plotting revenge, so he would need to keep a strong military presence.
If Robb won the war in a fanfic, it could lead to a completely different Westeros. He might establish a more just rule in the North and perhaps even expand his influence over other kingdoms. Maybe he'd form new alliances and bring about an era of peace and prosperity, unlike the chaos that followed in the original series.
It would change the storyline drastically. For one, many characters who died in the original story might survive. Robb's victory could mean a different fate for Sansa and Arya, as he would have more power to protect his family. Also, the political landscape would be very different. The Lannisters would be in a much weaker position, and that would affect how they interact with other houses.
Robb winning the war in the fanfic might be due to his ability to gain more support from the common people. If he promised fairer rule and actually delivered on it, more people would be willing to fight for him. He could also have some unexpected help, like a powerful but previously unknown group coming to his aid.
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.
One great fanfic could be where Robb finds Arya in a small village. He's overjoyed to see his sister alive. The story might focus on their emotional reunion and how they plan to reunite with the rest of their family. It could also include some action scenes as they face threats on their journey back to safety.
I think it's hard to say for sure. Different characters have their moments and it's not straightforward to determine a clear winner.
One possible plotline could be that Robb manages to escape with a small group of his most loyal men. They then go into hiding, perhaps in the North, and start planning their revenge against the Freys and Boltons. Robb might also try to gather more allies, like the remaining Stark bannermen who are still loyal to him.
In the 'robb returns game of thrones fanfic', it's likely that the fanfic would focus on the impact of his return on the overall plot. For example, his return could reignite the Stark family's claim to the throne. It might also create a ripple effect on other characters. Some who were once his enemies might have to reevaluate their positions. Additionally, it could show how the common people would react to his return. Would they see him as a savior or a threat? And how would his return affect the other kingdoms? Would they be more likely to form coalitions with the Starks or try to oppose them even more fiercely?
One possible plot could be that Robb Stark manages to avoid the Red Wedding trap. Maybe he receives a tip - off from an unexpected source, like a disgruntled Frey servant. With this knowledge, he could turn the tables on his enemies. He might use his military strategy skills to ambush the Freys instead, and this could lead to a major shift in the power dynamics in the North, with Robb emerging as an even stronger leader.
Well, in a fanfic where Robb finds Arya, they could immediately start making plans to take back Winterfell. Arya's skills could be a great asset to Robb's military campaigns. They might also share stories of their experiences during their time apart, which could strengthen their bond.