I also like 'Villain Redemption in OK KO'. This fanfiction focuses on some of the villains in the show and gives them a chance at redemption. It shows a different side to them and explores their backstories in a way that makes you see them in a whole new light. It's a really cool take on the OK KO universe.
One common theme is friendship. Just like in the show, fanfictions often explore the relationships between KO, Rad, and Enid. They might go through challenges that test their friendship, but in the end, they always come out stronger.
One possible plot idea could be that Ko and Dendy team up to face a new super - villain in the city. They might start off with some misunderstandings, like Ko thinking Dendy is too bossy with her scientific approach, but then they realize they need each other's skills to defeat the villain.
Definitely Enid from 'OK KO let's be heroes'. She has her own unique fighting style and a cool personality. In a crossover, she could team up with characters like Dipper from 'Gravity Falls'. Dipper's knowledge of the supernatural and Enid's combat skills would make for an interesting duo.
One idea could be an OC who has a unique power related to time manipulation. They could accidentally freeze time in the plaza and have to figure out how to unfreeze it without causing chaos. Another plot could involve an OC from a different dimension coming to Lakewood Plaza Turbo and trying to adapt to the strange rules and heroes there. Maybe the OC has a power that is considered a curse in their own dimension but could be useful in Ok Ko's world.
One possible plotline could be Enid dealing with the challenges of pregnancy while still trying to be a hero. She might struggle to balance her superhero duties with her physical condition. For example, she could be worried about putting herself and the baby in danger during battles.
One idea could be a crossover with another popular animated show like 'Steven Universe'. OK KO could end up in Beach City and have to team up with Steven to fight off a new type of gem - infected villains. They'd combine their unique powers, like OK KO's power fist and Steven's shield, to take on the bad guys.
There could be a fanfiction where Carol and Enid go on an adventure together in the world of Ok Ko! Let's Be Heroes. Maybe they discover a new power that has a lemon - like essence. They could face challenges and their friendship could grow stronger through it all.
First, consider the OC's origin. They could be from a far - off planet or a hidden underground civilization in the Ok Ko world. This gives them an air of mystery. Next, their power should be something that hasn't been seen before or at least has a unique twist. For instance, an OC that can transform into any object but can only do it when they're singing a specific song. Regarding their personality, make them complex. They could be generally kind but have a short temper when it comes to people disrespecting nature. This combination of elements will make your OC stand out in Ok Ko Let's Be Heroes fanfiction.
In the fanfiction, their relationship might develop through shared experiences. Maybe they go on a mission together that goes wrong, and they have to rely on each other to survive. This could lead to a deeper understanding and friendship. Ko could start to see Dendy not just as a smart girl, but as someone he can really count on. Dendy, on the other hand, might see Ko in a new light, as more than just a heroic type, but also as a friend who has her back. They could start to have inside jokes and a more relaxed rapport. As more adventures unfold, this bond could potentially turn into a romantic relationship if the writer chooses to take it that way.
I've heard of a fanfiction titled 'Crossover Clash: Ok Ko vs Nexus'. In this story, there's a sort of conflict that arises between the two universes. It's full of action and adventure as the characters from both sides have to figure out how to deal with each other. It also has some really interesting character development moments for both Ok Ko's and Nexus' characters.