Some fans enjoy crossovers with other superhero universes. For example, 'Game of Thrones' and 'Marvel'. Picture Iron Man trying to broker peace in Westeros or Thor facing off against the White Walkers. It's a really wild concept that can lead to some very entertaining and out - of - the - box fanfiction stories.
One popular crossover is 'Game of Thrones' with 'Lord of the Rings'. The epic fantasy worlds blend well together. You can see characters from both universes interacting in unique ways, like Aragorn meeting Jon Snow. Another is 'Game of Thrones' and 'Harry Potter'. Imagine the magic of Hogwarts in the brutal world of Westeros. It creates really interesting storylines.
One great crossover could be a scenario where the dragons from 'Game of Thrones' are used in the battles of Middle - earth in 'Lotr'. For example, imagine Smaug - like dragons fighting alongside the orcs against the free peoples. Another interesting idea is to have characters from the two universes meet. Maybe Arya Stark could end up in Middle - earth and learn some of the elvish skills in combat and stealth. There could also be a crossover where the magic systems interact, like the wizards in 'Lotr' trying to understand the power of the White Walkers in 'Game of Thrones'.
The Mandalorian himself is quite popular. His cool armor, mysterious past, and bad - ass fighting skills make him an interesting addition to the Game of Thrones universe. He can interact with the different houses and factions in unique ways.
A possible crossover could be Ultron taking over the body of a White Walker. This would give him control over the undead army and a terrifying presence in the North of Westeros.
Well, Daenerys Targaryen is often a popular choice. Her dragons and her journey of reclaiming the Iron Throne can be easily adapted into crossovers. For example, if she were to cross into a world full of magic - users, how would she use her power? Also, Jaime Lannister is quite popular. His character arc from a seemingly villainous knight to a more complex figure can be explored in different settings. In a crossover with a historical setting, his knightly skills and code of honor (or lack thereof at times) would be very interesting to play with.
Cersei Lannister could also be a popular choice. Her cunning and thirst for power in Game of Thrones could be enhanced in the Overlord fanfiction world. She could use her wits and the resources of the Lannisters to become a powerful Overlord - like figure, perhaps even making deals with the dark forces often associated with the Overlord concept.
One idea could be that Oliver Queen somehow gets transported to Westeros. He could use his archery skills to survive in the dangerous world. Maybe he'd join a faction, like the Night's Watch, and teach them his modern combat techniques.
You can try fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. AO3 has a large collection of fanfiction, and you can use the search function to look for 'Game of Thrones crossover' stories. FanFiction.net also has a lot of content, though the interface might be a bit different. Just type in the relevant keywords, and you'll likely find some interesting crossovers.
One of the great ones I've read is a crossover with 'Lord of the Rings'. It was really interesting to see how the different magic systems and cultures interacted. For example, the way the White Walkers were compared to the Ringwraiths was quite unique. The author did a great job of weaving the two complex worlds together without losing the essence of either 'Game of Thrones' or 'Lord of the Rings'.
In some fanfiction, the powerful magic in 'Game of Thrones' could be used to protect the endangered species on 'Planet Earth'. For instance, a wizard from Westeros could use spells to safeguard the pandas in China or the polar bears in the Arctic. It would be a unique way to combine the two universes.
The crossover where Naruto's shadow clones are used in the battles for the Iron Throne is really interesting. It gives a new dynamic to the warfare in 'Game of Thrones'.