Power is a very common theme. Since Tywin is all about power in the original story, fanfictions often explore how he gains, maintains, or loses power in different scenarios. Family dynamics is another one. His relationship with his children, especially Tyrion, Jaime, and Cersei, is always a rich area for exploration in fanfictions.
There could be a fanfiction that focuses on an alternate universe where Tywin survives longer. In this story, he would have to deal with the changing political landscape after the events at King's Landing. He might try to regain control of the situation, perhaps by making alliances with unexpected parties. His character would be forced to adapt to new threats and challenges, which could lead to some very interesting plot developments.
One possible aspect of Tywin Lannister and Sansa fanfiction could be the power dynamics at play. Tywin is a shrewd and powerful man, while Sansa is young and has been through much. In fanfiction, their interactions might range from Tywin seeing Sansa as a political pawn, which could lead to a complex relationship where Sansa has to navigate his machinations. Maybe she tries to use her charm and wits to gain some advantage in the cut - throat world of Westeros politics. It could also explore how Sansa's experiences with the Lannisters in general shape her relationship with Tywin. For example, her hatred for Joffrey and Cersei might initially make her very wary of Tywin, but over time, she could come to see him in a different light as she realizes he has different motives and methods compared to his more volatile children.
One great 'Game of Thrones Tywin Lannister Fanfiction' is 'The Lion's Legacy'. It delves deep into Tywin's past, showing his rise to power in a very detailed and engaging way. The author does an excellent job of portraying his complex personality.
In such fanfiction, the relationship can be complex. Tywin Lannister is a complex character. An OC (Original Character) might be drawn to his power and authority at first. But his cold and calculating nature could also create conflict. For example, the OC might try to humanize him, which would be a difficult task considering his reputation.
There are several good ones. 'Tywin's Ascent' is a fanfic that details his rise to power. It gives a lot of background on his family and the challenges he overcame. 'The Mind of Tywin' is really interesting as it tries to get into his thought process. It shows how he made decisions that shaped the Westeros we know. And 'Tywin's Last Stand' is a fanfic that imagines his final days in a very creative way.
In Tywin Lannister x Sansa fanfiction, a frequently seen theme is the transformation of Sansa. Under Tywin's influence, she could be transformed from a naive girl into a more politically astute woman. Also, the theme of loyalty is important. Sansa's loyalty to her family and her house is put to the test when dealing with Tywin. Will she stay true to her Stark roots or be swayed by Tywin's offers? Additionally, the theme of revenge can come into play. Sansa may seek revenge against the Lannisters for what they've done to her family, and her relationship with Tywin can be a part of that revenge plot, either by using him or by directly opposing him.
The novelty of original characters. They can bring new perspectives to the world of Tywin Lannister. For example, an OC could be from a different social class and show us how Tywin interacts with those he normally wouldn't deal with.
In OC fanfiction involving Tywin Lannister and the Starks, Tywin's strategic mind is a central aspect of his portrayal. He is always looking for ways to strengthen his house's position. The Starks, on the other hand, are known for their integrity. An OC could be a healer, for instance, who treats the wounded from both sides during a battle. This OC's presence might lead to some unexpected interactions between Tywin and the Starks, like Tywin seeing the Starks in a more sympathetic light due to the OC's influence.
Some fanfictions have a plot where the OC has some knowledge or ability that Tywin wants to use for his own gain. As they work together, feelings start to develop. There might also be a plot where the OC is from a rival family, and their relationship is a secret that could have major consequences if discovered, adding a lot of suspense to the story.