First, think about their Saiyan powers and how they would translate in the My Hero Academia world. For example, a Saiyan's ability to increase power level could be like a quirk that gets stronger over time. Consider their backstory, like maybe they're a Saiyan from another planet who ends up in the MHA world. Also, their appearance can combine Saiyan features like a tail and spiky hair with the MHA style of clothing.
One plot idea could be that the Saiyan OC is mistaken for a new type of villain at first. As they try to prove they're not a threat, they start to make friends and learn about heroism. Another idea is that they discover a connection between Saiyan powers and some of the hidden secrets in the MHA world. Maybe there's an ancient power source that only a Saiyan can unlock.
To create a compelling dark OC in My Hero Academia fanfiction, start with a strong motivation. It could be envy towards the heroes' popularity or a desire for power at any cost. Their quirk should be something that can cause chaos, like a mind - control quirk but with limitations such as it only works on those with weak wills. Appearance - wise, they could have a scar or some disfigurement that adds to their intimidating factor. And don't forget to give them a name that suits their dark persona.
To make your Kid OC x My Hero Academia fanfiction stand out, explore unique relationships. Maybe your OC has a crush on Todoroki and tries to get his attention in a cute but clumsy way. Or they could have a rivalry with Mineta because they think his behavior is inappropriate. Additionally, don't forget to describe the world of My Hero Academia vividly. Mention the different hero agencies, the technology used, and the social hierarchy among heroes and villains.
Another theme is self - discovery. The grey OC has to figure out who they are and what they stand for. They're not following the typical hero or villain path, so they have to create their own identity. This often involves exploring their powers, their values, and their place in the world of My Hero Academia.
Love and romance can be a theme as well. The SI/OC could fall in love with one of the characters from the original series. It could be a slow - burn relationship with lots of obstacles, like differences in their hero goals or social status within the hero community. This adds a whole new layer of drama to the fanfiction.
Some good character traits could be kindness. In the world of My Hero Academia, where there's a lot of chaos, a kind - hearted OC can stand out. Also, determination. If she has a goal, like becoming a top hero or finding true love in a Yuri relationship, determination will drive her. And she could be creative, using her creativity to develop her quirk or come up with unique ways to solve problems.
First, give her a unique quirk. It could be something related to nature, like controlling plants. Then, develop her backstory. Maybe she comes from a family with no heroes but has big dreams. Also, think about her personality. Is she shy or bold? For example, if she's shy, her journey in the hero world could be about overcoming that shyness to shine.
The 'outsider' trope is popular. The fem OC could be a transfer student from another country or school, struggling to fit in at UA. Another is the 'underdog' trope. She might have a weak - looking quirk at first but turns out to be really powerful later. And the 'love - interest - to - the - main - character' trope also shows up a lot.
To create a compelling OC (Original Character) for a My Hero Academia reincarnation fanfiction, first consider their quirk. It should be unique yet fit within the world's power system. For example, a quirk like 'Elemental Mimicry' where the character can mimic the properties of different elements. Then, think about their backstory. Maybe they were an ordinary person in their past life who had a strong sense of justice. This could fuel their actions in the new world of heroes and villains. Also, give them flaws. A character who is too perfect is uninteresting. Maybe they're overly impulsive or have a fear of heights which could add depth to their story.