Definitely genetic engineering. In a Game of Thrones fanfiction, this could be used in so many ways. It could be used to breed stronger and more resilient livestock, which is crucial for food supply. Or, in a more sinister way, it could be used to create some sort of super - soldiers. Houses could try to keep this technology secret or use it as a weapon against their enemies. It would also raise ethical questions among the maesters and religious leaders in Westeros.
I think the Internet would be really interesting. It would completely change the way information spreads in Westeros. People could communicate across great distances instantly. Nobles could use it for political propaganda, and commoners could use it to organize against unfair rulers. It would also change the way knowledge is shared, like maesters could access a world of information instead of just what's in their libraries.
For me, it has to be renewable energy technology. In a world like Westeros that's so reliant on natural resources like wood for fuel, solar panels or wind turbines would be revolutionary. It could change the economy as houses start to invest in these new energy sources. Also, it could have an impact on the environment, which in turn affects farming and the availability of food. Plus, it might lead to new alliances and rivalries based on who controls these new energy technologies.
Well, if we consider modern tech in Westeros in a fanfic, guns would completely change the way battles are fought. Armies that get hold of gunpowder technology first would have a huge advantage. For example, the Lannisters with their wealth could potentially mass - produce guns and gain even more power. Also, communication technology like radios would make it easier for lords to control their lands and respond to threats quickly.
Modern tech would have a huge impact. Consider communication technology like the internet or mobile phones. Information could spread across Westeros instantly. This would prevent the kind of misinformation that often fuels the power struggles. For instance, Ned Stark might not have been wrongly accused if the truth could have been quickly spread. Also, in terms of transportation, airplanes or fast cars would make travel much quicker. Daenerys could have reached Westeros much faster to claim her throne, and perhaps prevent some of the chaos that ensued during her long journey with her dragons and ships.
Well, modern technology in a Game of Thrones fanfiction would completely disrupt the power dynamics. Consider the Internet. If Westeros had the Internet, knowledge would spread like wildfire. People would be able to learn about different cultures and ideologies quickly. This could lead to the rise of new political movements. In terms of warfare, drones could be used for surveillance or even as weapons. It would be a strange sight to see a Lannister army being monitored by a drone from afar. And imagine the shock on people's faces when they first see a tank roll into King's Landing.
One way is through communication. For example, instead of ravens, they could use some sort of magical - technological device that can send messages instantly. This would change the way alliances are formed and wars are planned. Another aspect could be in the area of weaponry. Maybe there could be some advanced crossbows or swords with built - in tech that gives an edge in battle. Also, in terms of transportation, rather than horses all the time, there could be some sort of steam - powered or magic - tech vehicles.
Perhaps a plot where the Dragonborn discovers an ancient power in Westeros that is related to their own Dragonborn abilities. They go on a quest to unlock this power, all while being hunted by various groups who either fear their power or want to use it for themselves. Along the way, they form unexpected alliances with characters from Game of Thrones, like a wildling or a maester. Their journey could take them to the far reaches of Westeros, from the Wall to Dorne, and they would have to adapt to the different cultures and challenges they face.
A great plot twist in such fanfiction could be that there is a hidden underground society in Westeros that has been secretly developing modern technology all along. When they finally reveal themselves, they use things like laser weapons to take over King's Landing. Also, what if Bran Stark's warging ability could be enhanced by a neural - link technology? He could control multiple animals or even people at the same time, which would give him an incredible amount of power and change the balance of power in the story.
The Hulk might be seen as a sort of monster in the context of Game of Thrones. Just like how they have direwolves and dragons, the Hulk could be another mythical - but in this case, suddenly very real - creature. He could be shunned by some and perhaps worshipped as a god by others, depending on how different regions of Westeros react to his existence.
A plot where Deadpool somehow becomes a king would be really interesting. He'd probably run the kingdom in the most unorthodox way, making strange laws and having his own brand of 'justice'. For example, instead of beheading traitors, he might make them do stand - up comedy about their crimes.
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.
Naruto in the Game of Thrones universe might struggle with the moral ambiguity that exists there. In his own world, he has clear ideas of good and evil, but in Westeros, things are not so black and white. He may try to introduce his values of friendship and loyalty, which could either be embraced or rejected by the inhabitants of this new world.