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.
Hashirama would likely be a very powerful force in the Game of Thrones world. His skills as a shinobi and his ability to control nature could give him an edge. He might try to use his powers to bring peace, similar to his goal in his own world, but would soon realize the complex and cut - throat politics of Westeros.
You could combine characters by having a Roman character end up in Westeros. For example, a Roman centurion could be transported to Westeros and find himself in the middle of the War of the Five Kings. He could use his military training to fight for one of the sides or try to find a way back home.
Well, in a Game of Thrones fanfiction, a modern soldier could potentially change the power dynamics. Imagine a soldier with his combat boots and Kevlar vest suddenly appearing. He could use his military discipline to form alliances. He'd probably be shocked at first by the magic and dragons, but his ability to quickly assess situations and act could make him a valuable asset or a feared enemy. Maybe he'd try to introduce modern concepts like democracy or human rights, which would be very different from the feudal system in Westeros.
In a fanfiction, the Union Army could change the power dynamics completely. Their presence could force the different houses to either ally with them or against them. If they were to support a claim to the Iron Throne, that person's chances would increase significantly. But they would also face opposition from those who see them as outsiders and a threat to the traditional ways of Westeros.
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.
Well, it depends on the skills the modern person has. If they are into martial arts in the modern world, they could potentially use some of those fighting skills in 'Game of Thrones'. But they would still face challenges. The political intrigue is so complex there. A modern person might accidentally break some unspoken social rules and get into trouble. For instance, not knowing how to properly address a noble could lead to serious consequences.
Jon Snow was exiled to the Night's Watch again after killing Daenerys. Arya Stark set sail to explore the unknown west. Sansa Stark became the Queen in the North, ruling independently. Tyrion Lannister served as the Hand of the King to Bran Stark.
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.