One idea could be a crossover adventure where Sonic and Samus team up to stop a powerful, universe - threatening villain. They could combine their unique abilities, like Sonic's speed and Samus' combat skills and advanced weaponry.
Perhaps in the fanfiction, Samus is on a mission to retrieve a powerful and corrupted video game cartridge. This cartridge is causing glitches in the entire gaming universe. AVGN, being the self - proclaimed video game expert, joins her. Along the way, they have humorous exchanges as Samus tries to understand AVGN's strange references to retro games and bad game design.
One idea could be a race between Naruto and Sonic through different dimensions. Naruto could use his shadow clones to create distractions while Sonic zooms past. Another idea is a team - up to fight a common enemy that has the ability to disrupt both their worlds, like a villain who can steal chakra and chaos emeralds. Maybe Sonic could teach Naruto some of his super - speed techniques in exchange for learning some ninja skills.
One idea could be that Sonic and Kirby team up to save their respective worlds from a common enemy. Maybe a powerful dark force is threatening both Mobius and Pop Star. They could combine their unique abilities, like Sonic's speed and Kirby's inhaling and copying powers to defeat the foe.
One idea could be a crossover adventure where Megaman X and Samus team up to fight a common enemy that threatens both of their worlds. They could start off as rivals, not trusting each other's methods at first, but as they face challenges together, they learn to respect and rely on one another.
In some fanfictions, they might explore the differences in their personalities. For example, Classic Sonic's more simplistic and straightforward approach contrasted with Modern Sonic's more complex and sometimes cocky attitude. They could start off not getting along due to these differences but then learn to work together. Maybe there's a story where they are both trapped in a strange dimension and have to rely on each other's skills. Classic Sonic's spin - dash and ability to handle more 2D - like terrains, while Modern Sonic can use his homing attack and boost in the more complex 3D areas of the dimension.
One idea could be that Sonic from Sonic X accidentally travels to the Sonic Boom universe and has to adapt to the different environment and new versions of his friends. Maybe he teams up with Sonic Boom Sonic to defeat a common enemy that has found a way to cross between the two universes.
There could be a plot where Samus is sent to the Zelda universe to investigate some strange energy readings. There, she meets Link, and they initially distrust each other. But as they face various challenges together, like fighting off hordes of monsters and solving ancient puzzles, they grow closer. Another idea is that a group of interdimensional thieves steal something important from both Link and Samus. So, they have to work together to track down these thieves across different dimensions.
Well, you could focus on Sonic's origin story in the Sonic X Rewritten fanfiction. Maybe there was a long - lost civilization that was responsible for his super speed. Or you could have a plot where Sonic loses his speed for a while and has to rely on his other skills and the help of his friends to get it back. And a time - travel plot would be cool too. Sonic and his friends could go back in time to prevent a disaster that would change the future of their world.
One idea could be an OC who has the power to manipulate time and accidentally disrupts the Sonic universe's timeline. Another could be an OC from a different dimension that teams up with Sonic and friends to fight a new threat that endangers both their worlds. Or an OC that has a special musical ability which can either heal or boost the powers of the characters in Sonic X.
One idea could be Sonic and Merlina going on an adventure through different dimensions. Another could be a story where Merlina tries to use her magic to help Sonic defeat a new powerful enemy. And a third could be a more comical plot where Sonic has to teach Merlina about the modern world.