Probably Percy Jackson from 'Heroes of Olympus' and Magnus Chase. Percy is like the main hero in his series and Magnus is the main character in his. It makes sense that they would be the first to cross paths, maybe because of some strange magical event that throws them together.
Well, perhaps there's a prophecy in both the Greek and Norse worlds that foretells the coming together of heroes from both sides. So, the characters from 'Heroes of Olympus' and 'Magnus Chase' meet up to figure out what this prophecy means. They initially have some misunderstandings due to the differences in their cultures and mythologies, but as they start to share their knowledge and skills, they realize they need to work together. They then find out that an ancient evil, which was once sealed away by the combined powers of the Greek and Norse gods, is starting to break free. And they are the only ones who can stop it by combining their powers and using the unique abilities of each character from both series.
The interaction would be complex. The heroes of Olympus have their own personalities and powers. Some might be afraid of Godzilla, while others would be more curious. For example, Leo, with his mechanical skills, might wonder if he could build something to either communicate with Godzilla or defend against it. On Godzilla's side, it doesn't have the same kind of intelligence as the demigods. It would respond to their presence based on its basic survival and territorial instincts. So there could be a lot of miscommunication and misunderstandings between the two groups at first.
Doctor Strange and Ajak. Doctor Strange is well - versed in the mystic arts and Ajak has a lot of knowledge about the Eternals' history and their connection to the Celestials. Their knowledge areas could intersect, and they would likely be the first to start sharing information. Maybe Strange senses some strange energy related to the Eternals and approaches Ajak to find out more.
I think Annabeth from Heroes of Olympus and Bruce Banner (The Hulk) could get along. Annabeth is super smart and strategic, and Banner is a brilliant scientist. They could exchange knowledge about different fields like Annabeth's knowledge of architecture and ancient history and Banner's scientific research.
Well, it could be Twilight Sparkle and Spongebob. Twilight is the intelligent and studious one in My Little Pony. She would be intrigued by Spongebob, who is clearly a very different kind of creature from Equestria. Spongebob, on the other hand, would be in awe of Twilight's magic and knowledge. Their first meeting might happen when Spongebob is exploring the library in Ponyville that Twilight often frequents. She would start asking him questions about where he came from and what his world is like.
Leo Valdez is another character who could be a star. His ability to create and manipulate fire can add a lot of excitement to party games. He could be involved in a game where he has to use his fire to light up targets or keep a magical fire - based object alive for a certain amount of time.
The interaction between Iron Man and Magnus Chase would be fascinating. Iron Man is all about science and technology, while Magnus is from a world of magic. Iron Man would probably be very skeptical of Magnus's magic at first, trying to find a scientific explanation. Magnus, on the other hand, might be in awe of Iron Man's high - tech suit. Their conversations could range from friendly banter to serious debates about the nature of power, whether it's magic or technology.
Obviously, the main characters would include the Seven. They are a group with their own unique identities and abilities. And then there's Magnus Chase. He is also a central figure in this fanfiction. Each member of the Seven, like Percy Jackson for example, brings their own story and skills to the mix. Magnus Chase has his own set of powers and a backstory related to Norse mythology. Together, they form the main cast of characters in this fanfiction.
Interaction might involve a bit of competition too. The demigods are used to physical combat and using their powers in a more direct way. The wizards, with their spells, might seem a bit sneaky to the demigods at first. However, they could learn from each other. A demigod could learn how to use a disarming spell, and a wizard could learn how to fight without relying on a wand from the demigods.
It could be Zane from Ninjago and Trixie from Slugterra. Zane is very logical and has a lot of knowledge about technology and combat strategies. Trixie is smart and resourceful in the world of Slugterra. They might cross paths while investigating some strange occurrences that seem to be related to the crossover. Their initial meeting would probably involve a lot of questions and mutual curiosity as they try to figure out where the other is from and what they are doing in this new, combined situation.