Well, Darth Vader's presence in Game of Thrones would disrupt the existing social order. His power is not based on birthright or military might in the traditional Westerosi sense. He doesn't care about the Iron Throne as much as he cares about his own sense of purpose which is often tied to the dark side of the Force. This would make him an enigma to the people of Westeros. The common folk might see him as a bringer of doom, while the lords and ladies would be scrambling to figure out how to either use him or get rid of him. His ability to sense things through the Force could also give him an edge in the game of whispers and secrets that is so prevalent in the Seven Kingdoms.
He would be perceived as a very powerful and fearsome being. His black armor and the red glow of his lightsaber would make him stand out. People in Westeros have never seen anything like him before, so they would likely be both in awe and terrified.
The characters in Game of Thrones are used to political intrigue and regular combat. Darth Vader's use of the Force for things like mind control and telekinesis would seem like some sort of dark sorcery. Some might try to use him for their own gains, while others would see him as a threat that needs to be eliminated at all costs. His stoic and emotionless demeanor would also be very different from the passionate and often devious characters in the show.
If Darth Vader were in the Game of Thrones universe in a fanfic, he'd likely be a major disruptor. He could easily overpower most of the characters physically. However, the political intrigue might initially baffle him. But his strategic mind from the Star Wars universe could soon adapt. For example, he could form alliances with certain houses, perhaps using his power to intimidate them into cooperation, all while trying to achieve his own goals, whatever they might be in this new and strange world.
One idea could be that Darth Vader would use his Force powers to manipulate the political situation in Westeros. He might side with a powerful house, like House Lannister, and use his lightsaber to intimidate their enemies. His presence would completely change the power dynamics as his combat skills and the Force would be a huge advantage in battles and intrigues.
He would be a terrifying force. Just imagine him facing off against the White Walkers. His lightsaber could cut through them with ease, and the Force might even have some effect on them. The characters in Game of Thrones would be both in awe and afraid of him. He could potentially change the outcome of the war against the undead.
Darth Vader would disrupt the power balance. He wouldn't care about the politics of Westeros in the traditional sense. Instead, he would seek to rule through fear. He might target the most powerful houses first, like the Lannisters or the Starks, to show his dominance. His Sith ideology would clash with the religions and beliefs of Westeros, causing unrest among the people.
They could intersect in a dream - like scenario. A character in Game of Thrones, perhaps a Targaryen with their prophetic dreams, dreams of Darth Vader. This could be a sign of an impending doom or a new power rising. In the Star Wars universe, Vader has dreams and visions as well. Maybe their dreamscapes merge, and they communicate in this ethereal realm, sharing knowledge and perhaps even influencing each other's destinies in their respective universes.
Naruto's ability to use chakra and Darth Vader's connection to the Force could potentially create a very powerful combination. For example, Naruto could use his chakra to enhance Vader's lightsaber strikes, making them even more deadly. Or Vader could use the Force to help Naruto better control his Nine - Tails chakra.
Darth Vader's training would make Harry more self - reliant. In the wizarding world, Harry often has help from his friends. But Vader would force him to rely on his own abilities more. Also, Harry's perception of good and evil might be blurred. Vader's teachings are not as straightforward as the ones in the wizarding world.
His powers would likely be seen as extremely strange and powerful. The people of Westeros have never seen anything like chakra or ninja techniques. They might think he's a sorcerer or a god sent to disrupt or save their world.
If Darth Vader travels to a time when he was still Anakin Skywalker, he might have a chance to redeem himself earlier. Seeing his younger self could make him realize the mistakes he made and try to change the path that led to his dark transformation. His character could become more complex as he battles with his past self's idealism and his current self's dark nature.
Well, it could be really cool. Maybe Harry discovers some dark power within the wizarding world that is similar to the Force in the Star Wars universe. And he starts to develop a Vader - like persona, with a dark cape and a menacing presence. He might use his magic in a more aggressive and controlling way, like how Darth Vader uses the Force.