One plot idea could be a race across different dimensions. Sonic, with his speed, Mario, with his jumping skills, and Yoshi, with his unique abilities, could be competing to find a powerful artifact lost in these dimensions. Another could be a team - up to stop an evil force that threatens both their worlds. The evil force might be trying to steal the chaos emeralds from Sonic's world and the power - ups from Mario's world. And a third idea is a friendship - building adventure where they have to help Yoshi find his long - lost family in a strange new land that combines elements of both Sonic and Mario's universes.
Well, a cool plot might be that Sonic, Mario, and Yoshi are all mysteriously transported to a new world that is a mix of their own. In this world, they have to work together to solve puzzles and defeat strange new enemies. For example, they might come across enemies that can only be defeated by Sonic's speed combined with Mario's stomp and Yoshi's tongue - lashing. Or perhaps there is a story where Sonic accidentally brings chaos to Mario's world while running really fast, and Mario and Yoshi have to help him fix it while also learning about each other's abilities along the way.
There might be a fanfiction where Mario and Yoshi have a special bond that allows them to communicate telepathically. In this story, they face a great evil that is threatening the Mushroom Kingdom. Yoshi is able to sense danger from afar and warns Mario. Together, they embark on a journey to defeat the evil and save their home. It could include exciting battles and close calls as they make their way through various levels.
Well, a plot could involve Yoshi getting lost in a strange new world and Greninja being the only one who can guide him back home. Along the way, they face various challenges that test their friendship. For example, they might encounter a powerful storm that Greninja has to use its ninja skills to shelter Yoshi from. And as they journey, they learn more about each other's cultures and become great friends.
A plot idea could be that Cappy discovers he has a long - lost family in a hidden part of the Mushroom Kingdom. Mario and Cappy embark on a journey to find them. Along the way, they face off against a gang of Goombas who have been hired to stop them. Another idea is that an evil spell has been cast on Mario, making him forget all his skills. Cappy has to use his own wits and abilities to train Mario all over again, while also protecting him from the many dangers in the kingdom.
Sonic's speed can be used to quickly transport Mario and Yoshi across long distances. For example, Sonic could run on a loop - de - loop and launch Mario into the air for a super high jump, and Yoshi could then use his tongue to grab Mario and land safely. Also, Mario's ability to break blocks could be used to clear paths for Sonic to run through at full speed, and Yoshi could eat enemies that Sonic might not be able to easily avoid while running.
One idea could be that Sonic and Mario have to team up to save both their worlds from a new, powerful villain who has the ability to manipulate time. This would force them to use their unique speed and jumping abilities in new and creative ways.
Well, a cool plot for Mario Sonic crossover fanfiction might involve a new character that can travel between their worlds freely and is causing chaos. Mario and Sonic initially suspect each other but then realize they need to join forces. For example, this character could be stealing power - ups from Mario's world and Chaos Emeralds from Sonic's world to gain ultimate power. They would have to explore both worlds, facing their respective villains' minions along the way.
One idea could be that Mario and Sonic have to team up to save both their worlds from a new, powerful villain that is threatening to merge their dimensions in a chaotic way. For example, Bowser and Dr. Eggman could accidentally awaken an ancient evil while arguing over who is the better baddie.
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.