Percy's water - based powers and Magnus's ability to communicate with the dead could create some really interesting scenarios. For instance, Percy could use water to expose hidden passages in cemeteries where Magnus could then communicate with the spirits to get information.
Another idea is a setting where the two worlds are merging. Percy and Magnus find themselves in a strange new place that has elements of both Camp Half - Blood and the Hotel Valhalla. They have to figure out how to survive in this new world while also dealing with the chaos that the merging is causing. The characters from both series could interact in interesting ways, like Annabeth and Samirah comparing their knowledge of architecture and magic respectively.
First, do your research on both series. Know the characters, their abilities, and the rules of their respective worlds. For example, Percy can control water because he's Poseidon's son, and Magnus has the power of Sumarbrander, his magical sword. When you write their interactions, make sure it's consistent with their personalities. Percy is often impulsive and loyal, while Magnus is more laid - back and has a sarcastic sense of humor. Make sure their dialogue reflects this.
If Percy reads positive fanfiction about Magnus, he might develop a new - found respect for him. He could start to think of Magnus as more of an equal in the world of demigods, even though they are from different mythologies. For instance, if the fanfiction shows Magnus doing heroic deeds, Percy would recognize the similarities between their roles as heroes. However, if the fanfiction portrays Magnus in a negative way, Percy might be a bit more cautious around him, wondering if there's some truth to those made - up aspects.
Well, it's really hard to say. Percy has his water powers and his combat skills which are no joke. But Magnus has his own set of powers and his connection to Norse mythology is super strong. If it's a battle in water, Percy might have the upper hand. However, if it's in a more Norse - related environment like a frozen tundra or near a great hall in Asgard, Magnus could use the elements of his world to his advantage.
One idea could be a quest where Magnus and Percy have to team up to retrieve a powerful artifact that is causing chaos in both their worlds. Maybe it's an ancient Norse and Greek combined relic that only their combined skills can handle.
Percy's water - based powers could interact interestingly with Thor's lightning. For example, water is a great conductor, so if Thor were to strike Percy's water constructs, it could create a powerful blast. Or Percy could use his control over water to create a shield against Thor's lightning, diffusing it in a spectacular show of power.
I really like the idea of Percy and Magnus just chatting about their lives. Percy talking about his experiences with the Greek gods and Magnus sharing his Norse - related adventures. It would be a simple but really engaging interaction.
One great fanfic is 'The Adventures Beyond Borders'. It combines the worlds of Magnus Chase and Percy Jackson in a really cool way. The characters interact in a believable manner, and the plot is full of action and adventure. It has some really exciting fight scenes and also delves into the relationships between the different characters from both series.
One interesting crossover could be the characters from both series teaming up to fight a common enemy. For example, Magnus and Percy joining forces against a powerful ancient monster that threatens both the Norse and Greek worlds. This would be exciting as they both have different powers and abilities that could complement each other.
One interesting crossover could be a quest where Magnus and Percy have to team up. They could combine their different powers, like Percy's water - based abilities and Magnus's connection to Norse mythology. For example, they might face a sea monster that has a connection to both Greek and Norse realms. Another could be a story where they end up in each other's worlds and have to adapt. Percy in the Norse world would be really fun to read as he tries to figure out the different rules and gods there, and vice versa for Magnus in the Greek world.