Well, a really interesting plot twist in a Magnus Chase vs Percy Jackson fanfiction could be that they are both actually part of a prophecy that was misinterpreted. Instead of being enemies as some might think in a vs scenario, they are actually the keys to saving both the Greek and Norse worlds from a greater evil. Also, what if they end up in a world where the rules of both mythologies are all mixed up? For example, the sea in this world is made of mead from Norse mythology and the sky is filled with Greek monsters. How they navigate this strange new world would be full of twists and turns.
One interesting plot twist could be that they find out they are related in some way through the complex web of mythology. Maybe there's a long - lost ancestor who was part of both Greek and Norse worlds. Another could be that they are forced to swap powers. Percy has to deal with Magnus's Norse magic and Magnus has to handle Percy's water powers. It would be really cool to see how they adapt.
One interesting plot twist could be that Percy discovers a way to nullify Kratos' god - given powers. Maybe he finds an ancient artifact during the fight that has the ability to do so. Another could be that Kratos, instead of seeing Percy as an enemy, realizes they have a common goal against a greater evil in the fanfiction world and they end up teaming up.
One idea could be a crossover where Percy and Magnus have to team up to defeat a common enemy that threatens both their worlds. Maybe a primordial being that can disrupt the balance of both the Greek and Norse mythologies.
A really cool plot could be that there's a prophecy that involves both of them. The prophecy says that only by combining their unique abilities - Percy's control over water and Magnus's connection to the Norse gods - can they save both the Greek and Norse mythologies from being wiped out by a new, unknown force. They have to go on a journey, meet various characters from both mythologies, and overcome many challenges along the way.
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.
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.
Another pairing that might be popular is Jack (Magnus' sword) and Riptide (Percy's sword). It's a more unique and humorous pairing as fans might write about the two sentient weapons having conversations or competing with each other in some way.
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. Maybe there's a new threat that combines the Norse and Greek mythologies, like a monster that has the powers of both a Greek hydra and a Norse dragon. They would have to use their different skills and knowledge to defeat it.
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.
Another common theme is character relationships. This could be romantic relationships, like a pairing between a Magnus Chase character and a Percy Jackson character. Or it could be friendships, exploring how characters from the two different series would be friends.