A more complex plot could be centered around a shared threat. There could be an ancient evil that exists in both the Bloodborne universe and the Game of Thrones world. This evil starts to seep into Westeros, and characters from both universes have to come together to fight it. The hunters from Bloodborne would bring their unique weapons and fighting styles, while the characters from Game of Thrones would contribute their political intrigue and military strategies.
The plot could involve a crossover of the powers. In the world of Bloodborne, there are powerful blood-based abilities. Imagine if a character like Daenerys Targaryen got access to some of these powers. She could become even more of a force to be reckoned with, using the blood powers along with her dragons. It would change the power dynamics in Westeros completely.
Gascoigne from Bloodborne and Jon Snow would make for an interesting duo. Gascoigne is a fierce hunter, and Jon Snow is a great warrior. They could fight side by side against the White Walkers. Gascoigne's experience in hunting monstrous creatures could be invaluable in the fight against the undead, and Jon Snow's leadership skills could help in coordinating their efforts.
One possible plot could be Merlin, with his magic, finding himself in the world of Game of Thrones. He might use his powers to try and influence the power struggles. For example, he could help Daenerys control her dragons better or assist Jon Snow in his fight against the White Walkers. Maybe he would be seen as a sorcerer from a far - off land and have to prove himself to the different factions in Westeros.
Well, perhaps Deadpool gets transported to Westeros. He might side with the Starks at first, thinking they are the underdogs like him. But then he realizes how complex the politics are and starts playing all the houses against each other just for his own amusement.
Perhaps Bella could be a key figure in a crossover. She could be a 'dragon rider' in a sense, using her connection with Edward (similar to the bond between a dragon and its rider in Game of Thrones). Her immunity to vampire powers could translate to some sort of immunity to the dark magic in Westeros. The werewolves from Twilight could be allies with the Stark direwolves, and together they fight against common enemies, like an army of the dead led by a Volturi - like figure.
One possible plot could be that the Winchesters from Supernatural end up in the world of Game of Thrones. They could be on a hunt for a demon that has somehow found its way into Westeros. Maybe this demon is influencing the actions of some of the power - hungry lords, like Littlefinger. The Winchesters would have to navigate the complex politics of the Seven Kingdoms while also trying to figure out how to exorcise the demon without getting caught up in the wars for the Iron Throne.
Imagine that the Tesseract accidentally opens a portal between the Marvel universe and Westeros. The Avengers come through and are immediately caught in the middle of the War of the Five Kings. Tony Stark might befriend Tyrion Lannister, both being intelligent and a bit of an outcast in their own worlds. Thor could find common ground with the Red Priests who worship the Lord of Light, as it has some similarities to his own beliefs. The Avengers would then have to choose sides in the war while also preparing for the greater threat of the Others, which they learn about from the Night's Watch.
One interesting plot could be that AOC (assuming it's a character from another source) somehow gets transported to the world of Game of Thrones. She could use her modern - day knowledge and ideals to try and change the political landscape. For example, she might introduce concepts of equality and democracy to the feudal system of Westeros, which would surely stir up a lot of conflict among the different houses and power - hungry individuals.
In this fanfic scenario, the Infinity Gauntlet could also attract the attention of the White Walkers. If they got hold of it, they could use it to spread their icy grip across all of Westeros and beyond. They might use the Space Stone to teleport their armies, or the Time Stone to reverse the defeats they've suffered, making them an even greater threat to the living.
One aspect could be how the different power systems work together. In Man of Steel, Superman has his Kryptonian powers. In Game of Thrones, there are different forms of magic. A fanfic could explore if Superman's powers could interact with the magic in Westeros. Maybe his powers could be enhanced or weakened by it. And also, how would the people of Westeros react to an all - powerful being like Superman? Some might worship him, while others might see him as a threat to their power and status quo.
Well, one possible plot could be a humorous take within the GoT universe. Maybe a character is in a situation where they are extremely ticklish around the nipples area, and it leads to some comical misunderstandings. For example, during a tense negotiation, one character accidentally tickles another in that area, and it completely derails the serious atmosphere into a chaos of laughter.