The plot could involve Merlin being mistaken for a threat in the Game of Thrones universe. The maesters might see his magic as something dangerous and try to capture or kill him. Meanwhile, the various lords and ladies would be vying for his allegiance, thinking his magic could give them an edge in the game of thrones. He could end up caught in the middle of the war between the Starks and the Lannisters, using his wits and magic to survive.
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.
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.
Merlin would likely be in awe of Daenerys' dragons at first. He might try to communicate with them using his magic. Daenerys, on the other hand, would be both curious and cautious about Merlin. She would see his magic as a potential asset but also a threat to her rule. Jon Snow would probably respect Merlin's abilities and seek his help in the fight against the undead. He would be more open - minded compared to some of the other characters in Westeros.
A cool plot could be that the people of Westeros mistake Iron Man for some kind of powerful sorcerer because of his high - tech suit. The Lannisters might try to recruit him for their own gain. But Iron Man, being the hero he is, would see through their schemes. He could then start his own quest to find a way back home while also getting involved in the fight against the various threats in the Game of Thrones world. He might end up using the resources in Westeros to upgrade his suit in unique ways, like using Valyrian steel in its construction.
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.
The plot could center around a powerful artifact. In 'Game of Thrones', there are many powerful items like Valyrian steel swords. Suppose one such sword gets transported to the Marvel universe. Iron Man, being curious about new technology (even if it's more of a magical item in this case), starts to study it. This attracts the attention of both heroes and villains. Meanwhile, the character who owned the sword in 'Game of Thrones', say, Brienne of Tarth, travels to the Marvel universe to retrieve it. She teams up with Captain America, who admires her sense of honor. Together, they face off against villains like Loki, who wants to use the sword's power to take over the world.
Well, it could have characters like Jon Snow having a Pokemon partner like Arcanine. Arcanine is strong and loyal, much like Jon's direwolf Ghost. The story might involve battles for the Iron Throne where Pokemon are used instead of traditional armies. For example, Tyrion could use a Clefable, which is intelligent and sneaky, just like him.
One possible character arc for Merlin could be that he starts as an outsider, just like in his original story. He comes to Westeros and has to learn about the different cultures and politics here. As he gets more involved, he realizes the importance of using his magic for good in this new and dangerous world. He might start by helping the smallfolk, and then gradually get involved in the bigger power struggles, all the while maintaining his sense of right and wrong.