In many 'oc has a dark quirk fanfiction', you'll find the OC's family members as important characters. Their reactions to the OC's dark quirk can vary greatly. Some might be supportive and try to help the OC understand and control it, while others could be ashamed or scared. There could also be antagonists who are attracted to the power of the OC's dark quirk and try to either steal it or force the OC to use it for evil purposes.
Often, there are original characters created specifically for the fanfiction. These OCs are the main focus with their dark quirks. There might also be some canon characters from the original work that the fanfiction is based on. They could be friends, foes or mentors to the OC. For example, if it's a fanfiction based on a superhero story, there could be a well - known hero who tries to help the OC control their dark quirk.
The OC themselves is, of course, a central character. In addition, there could be other OCs who either have similar or contrasting quirks. They might form a group, like a team of misfits with different but equally interesting quirks. And then there are usually some authority figures in the fanfiction world. They could be teachers or leaders who are either afraid of the OC's dark quirk or see potential in it and want to train the OC to use it for good.
There could be a story where the OC's dark quirk is a secret at first. They are living a normal life until certain events start to trigger the quirk. The fanfiction might explore how they keep this secret from their friends and family. As the story progresses, they might be forced to reveal it when facing a powerful enemy that only their dark quirk can defeat. This could lead to a lot of drama, with their loved ones having to come to terms with this new side of the OC.
Well, Todoroki is frequently paired with Izuku in such fanfictions. Given Todoroki's own powerful quirk and his journey of self - discovery, he and Izuku with his voice quirk can have some great interactions. They might train together, and Izuku could use his voice quirk to help Todoroki better control his own quirk's temperature aspects. Momo is another one. As a smart and resourceful character, she could help Izuku understand the scientific aspects of his voice quirk, like how sound waves work and how to optimize his quirk usage. And of course, Iida. Iida's strict sense of justice and leadership could pair well with Izuku. He might encourage Izuku to use his voice quirk for the greater good and help him come up with strategies to use it in hero work.
One way is through self - sacrifice. If the character uses their evil quirk to save a lot of people at great personal cost, it could be a step towards redemption. For example, if their quirk is something like mind - control and they use it to stop a powerful villain who is about to destroy a city, but in the process they lose their own ability to use the quirk. Another way is by showing remorse and actively trying to make up for their past actions. They could start doing volunteer work in the community, using whatever skills they have (even if related to their quirk in a non - evil way) to help others.
Bakugo is often a key character. In many fanfictions, Bakugo's reaction to Izuku's evolving quirk can range from envy to begrudging respect. Their relationship is always a central focus, with Bakugo either trying to outdo Izuku or having to come to terms with Izuku's newfound power.
Bakugo is often paired with Izuku. Their complex relationship from the original series can be further explored in fanfiction with Izuku's growth quirk. All Might is also a common character paired with Izuku. He could play a role in guiding Izuku to control and develop his growth quirk. Ochaco is another one. She might be involved in stories where Izuku's growth quirk affects his relationships, especially romantic ones.
Bakugo is often paired with Izuku. Their relationship is complex in the original series, and in fanfiction with Izuku's time quirk, it could add more depth. Bakugo might be jealous of Izuku's new power at first but then come to respect it as they face challenges together.
One possible plotline could be that the oc with the evil quirk tries to hide it from others at first. They might be afraid of being ostracized. For example, they could pretend to have a normal quirk in public but struggle internally with the dark impulses their evil quirk brings. Another plotline could involve the oc being forced to use their evil quirk for self - defense in a dangerous situation and then having to deal with the consequences of others seeing what they can really do. Maybe they get hunted down by heroes who misinterpret their actions as villainous.
One idea could be an OC who discovers their psychokinesis quirk gradually. They start with small things like moving a pencil, then as they train, they can lift heavier objects. This can lead to an interesting story arc of self - discovery.
The OC could start as a shy and withdrawn character, afraid of their psychokinesis quirk. But as the story progresses, they gain confidence. For instance, at first, they might accidentally break things with their quirk and be scared, but later they learn to control it and become more self - assured.
Some characters might be immediately terrified. They could avoid Izuku or even try to drive him away. For example, classmates who don't understand his quirk might spread rumors about him.