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.
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.
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.
A possible plot could be that the Black Knight is wrongly accused of a crime. Rex and Generator Rex are initially tasked with capturing him. But as they get to know him during the chase, they realize he is innocent. So, they join forces to find the real culprit who is actually a powerful and corrupt figure trying to frame the Black Knight to gain more power in the post - apocalyptic world.
To write an 'Oc x Generator Rex' fanfiction, you have to understand the world of Generator Rex thoroughly. Research the existing characters, their relationships, and the overall story arc. For your OC, give them a clear motivation. Why do they want to be around Rex? Is it for protection, or do they have their own agenda? As for the relationship between the OC and Rex, show how they influence each other. Maybe the OC teaches Rex something new about the world he lives in, or Rex shows the OC how to be brave in the face of danger. Write in a way that keeps the readers engaged, with cliffhangers and interesting twists in the story.
You can try fanfiction websites like FanFiction.net or Archive of Our Own. These platforms have a vast collection of fan - created stories. Just search for 'Generator Rex' and 'Infinite Stratos' in the search bar, and you'll likely find some interesting fanfiction.