One common theme is the idea of an outsider. Jon Snow was an outsider in Westeros, and in Lord of the Rings fanfiction, he could be an outsider in Middle - earth as well. Another theme could be the battle against great evil, just like he fought the White Walkers in his own world, he could be fighting Sauron in Middle - earth.
Yes, there are quite a few. You can start by looking on fanfiction websites like Archive of Our Own. Some fanfics might combine the noble and brooding nature of Jon Snow with the epic fantasy world of Lord of the Rings in interesting ways, like having him be a lost traveler in Middle - earth or having some sort of magical connection between the two universes.
One common theme is identity. Jon is often exploring his true identity, whether it's his Stark - Targaryen heritage or his role as a bastard turned leader. Another theme is loyalty. His loyalty to the Night's Watch, his family, and the North is frequently explored. And of course, there's the theme of love. His relationships with Ygritte and other potential love interests are a big part of many fanfictions.
One common theme is the clash of different cultures. For example, when Middle - earth characters meet those from other fictional worlds, there are often misunderstandings at first due to different values and ways of life.
One common theme is self - discovery. Many original characters in the fanfiction are on a journey to find out who they are in the context of Middle - earth. For example, an OC might be a human with some elven blood and they are trying to understand both parts of their heritage.
One common theme is the clash of different powers. The high - tech powers of the Avengers against the magic in Middle - earth.
One common theme is the clash of different natures. Vampires, with their need for blood and immortality, are different from the races in Middle - earth. So, there's often a theme of how they are accepted or rejected. For example, elves might view them as abominations while humans might be more divided.
One common theme is family loyalty. Since they are both Starks, their loyalty to the family name and to each other as family members is often explored. For example, in many stories, they team up to protect the North and the Stark legacy.
Friendship is also a big theme. Many fanfictions focus on his relationships with Samwell Tarly and other comrades at the Wall. They show how these friendships help him survive and grow in that difficult environment. For example, they might go through challenges together like facing a wildling attack and their bond gets stronger as a result.
Love and relationships are also common themes. Fanfictions may explore his relationship with Ygritte in more depth, or create new romantic interests for him. His relationships with his family members, like his Stark siblings, are also often explored, showing the complex family dynamics and how they shape his character.
Well, a recurring theme is the revelation of his true heritage and how it impacts the overall plot of the 'Game of Thrones' universe. There's also the theme of loyalty. Does he remain loyal to the North or does his Targaryen side pull him towards other allegiances? And family is another theme. How does his newfound Targaryen family change his view of family compared to his Stark upbringing?