The uniqueness. The OC cats can have all kinds of quirks and personalities that we don't see in the original MHA. It's like adding a whole new element to the familiar world.
One great MHA OC cat fanfiction is 'The Cat - Hero in Disguise'. It features an OC cat with unique quirks that add an interesting twist to the MHA universe.
First, you need to create a unique villain OC. Think about their backstory, what made them turn bad. For example, if they had a tragic childhood event like being bullied or abandoned. Then, consider their powers. It should be something that fits the MHA universe. Maybe a power related to shadows or mind control. Also, give them a distinct personality. Are they cold - hearted, or do they have a soft side? When writing the fanfiction, start with an interesting hook to draw readers in, like a mysterious crime scene caused by your villain OC.
A lot of MHA female OC fanfiction involves the OC being part of a team. For instance, she could be in a team with some of the less - prominent characters from the original series and they go on to do heroic deeds. Some stories focus on the female OC's journey to master her quirk, perhaps with the help of an older, more experienced hero. There are also those that explore the OC's family background and how it ties into her life as a hero - in - training, like if her family has a history of quirks that were once feared or misunderstood.
Check out YouTube channels or podcasts that focus on MHA fanfiction. They sometimes do reviews or showcases of great MHA OC fanfictions. Additionally, following MHA fan artists on platforms like Twitter can also lead you to discover great fanfictions. Often, fan artists are also into fanfiction and can point you in the right direction.
There's 'A New Hope for UA' which is also a very good MHA OC fanfiction. In this, the OC has a quirk that is initially seen as weak but they manage to use it in innovative ways. The fanfiction does a great job of integrating the OC into the existing MHA universe, with lots of references to the original series.
First, develop a really interesting quirk for your female OC. It should be unique but also fit within the MHA world. For example, a quirk that allows her to manipulate time in a small area. Then, create a solid backstory. Maybe she grew up in a family that was against quirks at first but she had to fight to embrace hers. Also, make sure to give her a distinct personality. Is she brave and outspoken or more shy and reserved? This will make her character more engaging.
In MHA villain OC fanfiction, a mistake is not giving the villain OC a clear motivation. Just being evil for the sake of it is boring. Their actions should be driven by something, like a desire for revenge or power. Don't make their design too outlandish that it doesn't seem like it belongs in the MHA world. And don't forget about character development. If the villain OC is just static throughout the story, it won't be engaging. They should grow or change in some way, even if it's a downward spiral into more evil.
Well, you could have an MHA OC who is a villain - turned - hero. Their backstory could involve being mistreated and turning to villainy, but then being inspired by the heroes to change their ways. Maybe they have a quirk that involves shadow manipulation, which they used for evil before but now use for good. Or an OC that is a tech - genius and creates their own high - tech hero gear, much like Mei Hatsume but with their own unique style. Also, an OC with a healing quirk could be interesting, especially if they have to deal with the moral dilemma of whether to heal villains or not.
One common theme is self - discovery. The reincarnated OC often has to figure out who they are in this new world and how their previous life and new circumstances interact. Another is the struggle for power. Since the MHA world is centered around quirks, the OC usually has to find a way to gain power or use their unique skills.