Another plot could involve the Prince of Darkness being a key figure in a prophecy that the maesters have long ignored. As he emerges, he begins to gather followers who believe he is the answer to the chaos in Westeros. His actions could lead to a split between those who follow the traditional religions of the land and those who are drawn to his dark allure.
Many of the powerful noble houses would be his enemies. For example, the Lannisters, who are already in a struggle for power. They would not want to share or lose their power to the Prince of Darkness. And the Tyrells, who are also politically astute and would view the Prince as a threat to their influence and the stability of the Seven Kingdoms.
One plot idea could be that the heir is a long - lost Targaryen who was raised in Essos. They come to Westeros with a new set of values and ideas, trying to unite the kingdoms not through force but through trade and cultural exchange. This heir could face resistance from the traditional lords who are used to the old ways of power struggle.
In a 'Game of Thrones' and 'Sherlock' crossover, Sherlock's deductive skills could be used to solve the mysteries in Westeros. He could figure out who really poisoned Joffrey or find out the secrets of the Faceless Men. It would be interesting to see how his logical mind would interact with the more superstitious and political world of 'Game of Thrones'.
A unique idea could be Smaug being tamed by Bran using his warging abilities. Bran, with his connection to animals and his growing powers, might be able to reach out to Smaug's mind and form a bond. This would completely change the role Smaug plays in the 'Game of Thrones' universe.
A plot idea could be a story about a young, aspiring knight who comes to Harrenhal seeking glory but instead discovers a curse that plagues the castle. He then has to find a way to break the curse to save the people there.
One idea could be exploring what would happen if a minor character like Gendry had been secretly trained in magic. He could use his newfound powers to unite the smallfolk against the warring nobles. Another plot could revolve around a female knight from the North who disguises herself as a man to fight in the wars, and along the way, she discovers secrets about the White Walkers that no one else knows. Or perhaps a fanfiction where Daenerys and Sansa form an alliance much earlier and together they reshape the power dynamics of Westeros.
A plot could involve the Prince of Darkness in a battle against other supernatural forces. He has to team up with unexpected allies, like a group of young witches who are also trying to protect their world from a greater evil. This would lead to a lot of character development as they learn to work together.
One idea could be a scenario where a navy destroyer from the modern world somehow gets transported to the Game of Thrones universe. The crew has to navigate the political intrigues while also dealing with the technological advantage they have. Maybe they form an alliance with a particular house, like House Stark, and use their ship's firepower to help in battles against the White Walkers.
One idea could be exploring a new character who discovers a hidden power within the Darkness Game world. They might use this power to change the rules of the game in unexpected ways.
One idea could be exploring what would happen if a minor character, like Gendry, had a more central role in the fight against the White Walkers. He could lead a group of common folk and prove that the power doesn't always lie with the nobles.