One great fanfic could be one where Tormund shows his true leadership skills during the Battle of Winterfell. Maybe he leads a small group of soldiers in a heroic defense against the White Walkers, using his brute strength and his knowledge of the North.
Well, during the Night King's battle at Winterfell in the novel, the initial encounter with the undead hordes is a big part. The Dothraki charge, which was a spectacular but also a very tragic moment as they were mostly wiped out. Then there's the fight within the castle walls, where every character has to face their own challenges and fears, and they struggle to hold their ground against the seemingly endless waves of the dead.
Arya Stark was a main hero. She killed the Night King and saved the day. Also, Jon Snow was important as he led the defense and fought bravely against the undead. And Theon Greyjoy redeemed himself by protecting Bran during the battle.
One key event was the Dothraki charge at the beginning which was a spectacular but ultimately tragic start as most of them were wiped out. Another was the Night King's arrival and his showdown with Jon Snow. And of course, Arya Stark's unexpected killing of the Night King which turned the tide of the battle.
In the novel, the Night King's power at the Winterfell battle is quite evident. He has the ability to raise the dead on the battlefield, increasing his army size. His very presence also spreads a sense of cold and fear that affects the morale of the defenders. Moreover, his control over the White Walkers gives him a more organized and strategic force compared to just the mindless wights.
There could be a fanfic that ties Tormund's backstory to his actions in the Battle of Winterfell. For instance, if he had some sort of encounter with the White Walkers in his past, and that experience resurfaces during the battle, driving him to fight even more fiercely. This would add depth to his character in the context of the battle.
Power and influence. If a character can assert their authority over Winterfell, whether through political maneuvering like Sansa did in the show, or by being a forceful military leader, she could be seen as the real lady. For example, if a character rallies the troops of Winterfell against invaders and is successful, that would give her a strong claim.
Well, a 'bastard of Winterfell fanfic' could be about the story of a character who is a bastard in Winterfell. It might explore their struggles, their relationships within the Winterfell society, and how they try to find their place. Maybe it focuses on their journey of self - discovery, facing the prejudice that bastards often face in the world of Westeros. It could also involve their adventures, like getting involved in battles or political intrigues within the context of Winterfell.
In many 'Game of Thrones' fanfics, different characters could be considered the 'real' lady of Winterfell. It could be Sansa Stark, as she has a strong claim to Winterfell through her Stark heritage. She has endured a great deal and learned the ways of politics, which would make her a worthy lady of the keep.
Family is a very common theme. Since the Starks are a large and important family in Winterfell, many fanfics explore their family bonds, loyalty, and rivalries. Another common theme is survival, especially during the harsh winters that Winterfell often faces.