A villain OC with the power of illusion could be really cool. They could create elaborate illusions to deceive the heroes and the public. They might use these illusions to make it seem like they're attacking one place while actually targeting another. Their backstory could involve being an outcast in society who turned to villainy as a way to get revenge on those who shunned them.
One idea could be to create a villain OC who has the power to manipulate time in small increments. This could lead to really interesting scenarios in battles against the heroes. For example, they could slow down time just enough to dodge attacks and then speed it up suddenly to surprise their opponents.
Another interesting concept is a robot OC that was created by a villain but has a change of heart. This robot could struggle with its programming and new - found sense of morality. It might have to hide its true identity from both heroes and villains while trying to do good in the world of BNHA.
Maybe the Knuckle Duster has a hidden backstory that the OC discovers. The OC could be on a quest to find out more about the origin of the Knuckle Duster, which could involve delving into the history of some secret organization in the BNHA world. Along the way, they form alliances with other characters and face various challenges.
One idea could be a villain OC who has the power to manipulate dreams. They could enter the ponies' dreams and create nightmares, causing chaos and fear. This villain could be motivated by a desire for power over the dream realm.
One idea could be that the male OC is reincarnated as a villain in the BNHA world but has memories of his past life as a hero. So he struggles between his new villainous identity and his old heroic values. Another plot could be that he reincarnates as a quirkless character, like Midoriya was initially, but he uses his past - life knowledge to develop unique combat skills. Or perhaps he reincarnates as a powerful hero's sidekick and has to deal with living in the shadow while trying to prove his own worth.
A good plot could be a villain being sent to an alternate dimension where they experience a life without quirks. They see how normal people live and cooperate, and this makes them realize that their use of power for evil was wrong. When they return to their own world, they are determined to reform.
One idea could be a crossover where Naruto characters visit the BnHA world and learn about quirks. For example, Naruto might be intrigued by how different quirks work compared to chakra. Another idea is to have a character from BnHA end up in the Naruto universe and struggle to adapt to the ninja lifestyle. Maybe they try to use their quirk in a world that runs on ninjutsu and find it either very useful or completely ineffective.
A villain OC for a Supergirl fanfiction could be an alien from a dimension where Supergirl is seen as a tyrant. This OC comes to Supergirl's world with the mission to stop her 'tyranny'. The OC could have unique powers like the ability to manipulate time on a small scale. This would create interesting battles between the OC and Supergirl, as Supergirl tries to convince the OC that she is not a tyrant while also dealing with the OC's attacks. The fanfiction could also explore how the people of Supergirl's world react to this new villain who claims to be a liberator.
A villain oc who is a half - human, half - beast hybrid. They were outcast from society because of their appearance and now seek revenge on all the villages. They have unique physical abilities due to their hybrid nature, like super strength and enhanced senses. Or perhaps a villain oc who is a former student of a great ninja but turned against their teachings. They create their own new and dangerous form of ninjutsu that goes against the traditional ways.
I really like 'Villainous Intent: An OC's Tale'. This fanfic does a great job of integrating the OC villain into the existing BNHA world. It shows how the OC interacts with the well - known heroes and villains from the original story, and the plot twists are really exciting.
Often, bnha female villain oc in fanfic are highly intelligent. They need to be smart to outwit the heroes. They can plan elaborate schemes and manipulate situations to their advantage. Also, they tend to have a certain charm or allure. This helps them in getting what they want, whether it's influencing other characters or distracting their enemies. In addition, many of them are quite independent, not relying on others to achieve their goals.