One idea could be that Rex and Breach are forced to team up against a new, powerful EVO that threatens their mutual interests. Along the way, they start to understand each other's pasts and develop a grudging respect. For example, Rex could learn about Breach's difficult upbringing in the Nanite Collective and start to see her in a new light.
One possible fanfiction could be about Rex's adventures in a new, uncharted area where he discovers a strange new type of E.V.O. He has to use his powers in creative ways to deal with it and learn more about this new threat or ally.
Fanfiction about Rex and Six could also involve a mission where they are sent undercover. They have to pretend to be ordinary people in a community that is on the verge of being overrun by E.V.O.s. They need to figure out how to stop the E.V.O.s without blowing their cover, and in the process, they learn more about each other's personalities outside of the battlefield.
Rex's powers could be used in a unique way if he has to combine his different nanite - based abilities in a new and unexpected manner. For instance, instead of just using his Smackhands to fight, he could use them to create a shield for Breach when she's in danger. This would show his adaptability and his growing concern for her safety.
In a post - apocalyptic world, Generator Rex was on a mission. Rex was also exploring the same area. They both heard rumors of the Black Knight. When they finally met the Black Knight, he was not what they expected. The Black Knight had a code of honor. Rex was intrigued and Generator Rex was curious about his technology. They started to exchange knowledge. The Black Knight taught them some ancient combat techniques and in return, Generator Rex shared his knowledge of advanced machinery. Rex learned a lot from both of them and they became friends, vowing to protect the world together.
A fanfic could focus on Noah's perspective of being Rex's friend. Maybe Noah starts to feel a bit overshadowed by Rex's powers and has to deal with his own insecurities while still supporting Rex in their adventures. For example, during a mission where Rex is getting all the glory, Noah could be the one who actually figures out the key to defeating the EVO, but no one notices at first.
Another story could be set in a post - apocalyptic world where vampires have emerged as a result of some mutagenic event related to the nanites. Rex, being the only one with the ability to control his nanites, has to find a way to coexist with the vampires. He could encounter a vampire who was once a scientist and together they try to reverse the vampiric transformation in some people.
When writing Generator Rex fanfiction, it's important to stay true to the spirit of the original show while also adding your own creativity. For character development, think about how the events in your story will change the characters. Will Rex become more confident? Will his relationships with other characters evolve? Also, proofread your work carefully to avoid grammar and spelling mistakes. This will make your fanfiction more enjoyable for readers to read.
One idea could be a crossover where Generator Rex's nanites interact with the X - Men's mutant powers in unexpected ways. Maybe the nanites start to adapt and mimic some of the mutant abilities, causing chaos and confusion among both groups.
One idea could be that Naruto and Rex meet in a dimension where their worlds collide. Naruto's chakra powers and Rex's nanite abilities could create some really interesting battle scenes as they team up against a common enemy, like an evil organization that wants to control both their worlds.