In such a fanfiction, perhaps the concept of the Sharingan in Naruto could be related to some sort of immortality in the Game of Thrones universe. Characters with the Sharingan could see the future and avoid death, like they do in Naruto. They could then use this ability to manipulate the events in the Seven Kingdoms. They might side with different houses based on their own goals, all while trying to keep their immortality - related secret safe from those who would do them harm.
A really interesting take on this fanfiction could be that the tailed beasts in Naruto are linked to immortality in the Game of Thrones world. Imagine if a character in Westeros were to be possessed by a tailed beast. They would gain not only great power but also a form of immortality. This would completely disrupt the balance of power in the Seven Kingdoms. The character would have to deal with the political intrigue as well as the internal struggle of containing the power of the tailed beast, all while being an immortal force in a world that is not used to such things.
A Naruto - High School DxD fanfiction with the concept of immortality could start with Naruto being summoned to the DxD world by an unknown force. Since he's immortal, he doesn't fear death like many in the DxD world do. This could lead to him taking on more dangerous quests or getting involved in the wars between the different species. He could also use his immortality to experiment with different powers and techniques in the DxD world without the risk of dying, which would make him a very formidable and unpredictable character.
One idea could be to create a story where the ninjas from Naruto are inserted into the political intrigue of Westeros. For example, Naruto, with his strong sense of justice, could find himself in the middle of the power struggle for the Iron Throne. He might try to use his ninja skills to bring peace to the war - torn land, much like he did in the Hidden Leaf Village.
In a 'God Naruto Game of Thrones' fanfiction, Naruto's character would bring a whole new dynamic. His journey to become Hokage in his own world has made him strong - willed and determined. In the Game of Thrones setting, he might view the Iron Throne as something similar to being Hokage. However, the complex web of relationships and betrayals in Westeros would be a huge challenge for him. He'd have to navigate through the schemes of Cersei, Littlefinger, and others while also dealing with the threat of the White Walkers if the story takes place during that time period.
One idea could be a character who has the power of the Tailed Beasts from Naruto and uses it in the political intrigue of Westeros in 'Game of Thrones'. For example, they could use the power of the Nine - Tails to intimidate their enemies during a battle for the Iron Throne.
One idea could be a story where Kratos finds himself in the world of Westeros. Maybe he gets involved in the power struggles between the houses. He could use his combat skills to fight against the White Walkers, bringing a whole new level of action to the fight against the undead.
One idea could be to have Percy Jackson transported to the world of Game of Thrones. Maybe he arrives in Westeros and is mistaken for a powerful sorcerer because of his demigod powers. He could get involved in the power struggles between the different houses, using his skills in combat and his ability to control water to his advantage.
One interesting fanfiction could be one where the political intrigue of 'Game of Thrones' is set in the lost city of Atlantis. Maybe the houses of Westeros are reimagined as different factions in Atlantis, vying for control over the advanced technology or magical artifacts that Atlantis is rumored to possess.
One interesting concept is alternate endings. For example, some fanfictions might have Jon Snow actually ruling Westeros in a more peaceful way than in the original series. Another concept could be character crossovers, like if a character from another fantasy world entered the Game of Thrones universe. It adds a whole new layer of intrigue.
A 'God of War' and 'Game of Thrones' fanfiction might feature a crossover of their mythologies. The gods in 'God of War' could interact with the Seven in Westeros. For example, Zeus could have some sort of encounter with the High Sparrow. Kratos might also have a unique perspective on the power struggles in the Seven Kingdoms, having dealt with his own power - hungry gods in his world.
One great fanfic could be about a wizard from the Harry Potter world traveling to the Game of Thrones universe and taming a dragon there. Maybe they use magic to communicate with the dragon in ways that the people in Westeros can't even imagine.