Well, it could be a story where the values of the Roman Empire, such as honor and loyalty in the military, are introduced to the characters in 'Game of Thrones'. Maybe a character from the Seven Kingdoms travels to a land inspired by the Roman Empire and brings back new ideas. Or perhaps there are gladiator - like battles in the arenas of Westeros, with characters from both worlds competing for glory. It would be a wild mix of the two universes.
A possible main character could be a Westerosi noble who is intrigued by the Roman Empire and decides to journey there. He could be like Tyrion Lannister, smart and cunning, trying to navigate the new and strange world of the Romans. Another could be a Roman general who finds himself in Westeros and has to adapt to its different rules of war and power.
The common people from the Roman Empire would face a lot of difficulties. The harsh winters, the constant threat of war, and the feudal system in Westeros are very different from what they are used to. But some might be able to use their skills in farming, building, or trading to carve out a living in this new and dangerous land.
One interesting crossover could be the political intrigue. In 'Game of Thrones', the power struggles between different houses are intense. In the Roman Empire, there were also power struggles among senators and the imperial family. So, a fanfiction could explore how the political tactics from one world would play out in the other. For example, the Roman concept of patron - client relationships might be applied to the relationships between lords and vassals in Westeros.
One idea could be a story where the political intrigue of the Roman Senate is mirrored in the power struggles of the Great Houses in Westeros. For example, the patrician families in Rome could be compared to the noble houses in Game of Thrones, with similar backstabbing and alliances for power.
It could be really interesting. Maybe the characters from RWBY could be placed in the complex political landscape of Westeros. For example, Ruby could be like a young knight trying to prove herself in a world full of backstabbing and power struggles. Weiss might be a noble trying to uphold her family's honor in a different way than she does in her own world.
In such a fanfic, the story could follow Naruto's journey to become the Hokage but in the context of the Iron Throne. He would have to deal with the backstabbing politics of Westeros. His friends would be his allies, like Sakura as a healer like in Naruto, but also having to navigate the dangerous court politics. And the Akatsuki could be a group similar to the Night's Watch, but with their own evil motives.
A 'Game of Thrones' and guns fanfic could be really interesting. Maybe it would be set in an alternate Westeros where guns have been introduced. The characters would have to adapt to this new form of weaponry. For example, Arya Stark might use a gun instead of her Needle in some situations. It could also change the power dynamics in battles and political intrigue.
It's hard to say exactly, but probably there would be a lot less political fragmentation and maybe more advanced technology and cultural development.
In a 'John Wick Game of Thrones' fanfic, it could be a mix of the modern - day assassin vibes of John Wick and the medieval - like setting of Game of Thrones. John Wick might bring his own code of honor, which could either clash or align with the honor systems in Westeros. For instance, his loyalty to a cause or a person could be compared to the loyalty oaths in Game of Thrones. And his ability to track down his targets would be very useful in a world full of political enemies and traitors. There could be epic battles where he uses his signature gun - fu against swords and arrows. Also, his backstory as a former assassin trying to get out of the life could be paralleled with characters in Game of Thrones who are trying to break free from their fates or obligations.
It could be really interesting. Maybe Sherlock Holmes would be transported to the world of Game of Thrones. He would use his brilliant deductive skills to solve the mysteries in Westeros. For example, he could figure out who was behind the sudden deaths of some important lords, or he could discover the secrets of the White Walkers much faster than the people in the show.