One idea could be that the OC is a powerful warrior from a different dimension. They meet Kefla during a universal tournament. Their powers are so different yet complementary that they start to train together, and gradually a deep bond forms between them as they learn from each other's fighting styles.
The OC could be a scientist who is researching the unique energy that Kefla possesses. In the process of studying Kefla, they start to understand her personality beyond her power. Kefla, who is initially suspicious of the OC, begins to trust them as they show genuine interest in her and not just her abilities. This mutual understanding leads to an unexpected friendship and potentially more.
A possible plot could involve Kefla being sent to the Naruto world as part of a test by the Kais. In this world, she is intrigued by Naruto's determination. Naruto, on the other hand, is amazed by her power. They train together and learn from each other's fighting styles. This leads to a strong bond between them, and they end up protecting the Hidden Leaf Village from a powerful new threat.
One idea could be a story where Goku and Kefla have to team up to face a new, powerful enemy that neither could defeat alone. They start off not trusting each other much, but as they fight side by side, they learn to respect one another's strength and fighting styles.
One idea could be that the OC is a new arrival in a magical realm where Marecline is a powerful being. The OC has a special power that Marecline is intrigued by, and they start off as adversaries but gradually develop a mutual respect and an unexpected bond.
Another interesting plot could be that the OC is from another dimension and gets stranded in Gotham. Batman, being the detective he is, tries to figure out how to send the OC back while also dealing with the chaos the OC's presence causes in the city, as their technology or powers are not from this world.
An interesting concept could be an OC who is initially afraid of Digimon but is forced to team up with one. As they journey together, they gradually overcome their fear and develop a deep bond, learning important life lessons along the way.
One idea could be an OC who is a trainer from a far - off land coming to the well - known Pokemon regions to compete in the Pokemon League. Their unique training methods and the relationships they form with their Pokemon can be a great focus. For example, their OC might use music to soothe and train their Pokemon, which is something not commonly seen in the regular Pokemon world.
One idea could be an OC who is a scientist accidentally stumbles upon a Predator's hunting ground. The OC has to use their wits and scientific knowledge to survive and even form an unlikely alliance with the Predator. Maybe the OC discovers a way to communicate with the Predator through some sort of energy signal, which intrigues the Predator enough to not kill them right away.
One idea could be that the OC is a kind - hearted soul who gets lost in the forest on Krampusnacht. Krampus, instead of punishing them right away, is intrigued by their innocence. He decides to follow the OC and protect them from other dark forces in the forest while also teaching them about the balance of good and evil.
Another interesting idea is a time - travel based fanfiction. The OC accidentally travels back in time and meets Gowther in his past. This could lead to a lot of drama as the OC tries not to disrupt the timeline while also getting closer to Gowther. They could end up changing small things that have big impacts on their relationship.
One idea could be that the OC is a scientist who discovers a new form of Kryptonite and Superman has to work with the OC to keep it out of the wrong hands. The OC could also have a unique power that compliments Superman's, like the ability to control technology which helps Superman in battles against tech - based villains.