A cool concept for a Young Justice OC SI fanfiction is an OC who is a tech genius from a parallel Earth. In the story, their technology is far more advanced than what's in the Young Justice world. The SI element means they have to deal with the differences in culture and morality. They could use their tech skills to upgrade the team's gadgets and in the process, get involved in a big battle against a new super - villain who is attracted by their advanced tech. They also have to hide their true origin from the team at first because they're not sure if they can be trusted.
One idea could be to create an OC with a unique power like the ability to manipulate sound waves. The SI (self - insert) aspect could involve the character being from our world and suddenly thrust into the Young Justice universe. They could struggle to adapt to the new rules and powers around them while also trying to find a way to get back home. Maybe they form an unlikely alliance with a less - popular character and together they change the course of events in the story.
Some Young Justice SI OC fanfictions focus on the OC's relationships with the existing characters. For instance, an OC who forms a deep friendship with Robin. They might train together, share secrets, and the OC could even influence Robin's growth as a character. The SI OC could also have a romantic relationship with one of the other characters, which would create a whole new dynamic within the team and the story.
One idea could be creating an OC with unique powers like the ability to manipulate time on a small scale. For example, they can slow down time for a few seconds during a battle, which gives them an edge. Another idea is an OC from a different dimension who has to adapt to the Young Justice world while also bringing their own set of skills and knowledge. Maybe an OC who is a master of ancient martial arts from a dimension where that art form is the key to survival.
One idea could be an OC with unique powers joining the Young Justice team. For example, an OC who can manipulate time in small increments. This would create interesting scenarios during battles and team strategizing.
One idea could be an OC with a unique power, like the ability to manipulate sound waves. They could join the Outsiders and use their power in unexpected ways during battles, for example, creating sonic illusions to confuse enemies. Another plot could involve an OC who is from a different dimension and has to adapt to the Young Justice Outsiders' world while also bringing some of their own world's knowledge and technology. Or perhaps an OC who has a personal vendetta against a villain that the Outsiders are also after, and they initially clash with the team but then learn to work together.
One idea could be to create an OC who is a former victim of the Joker's madness and now has powers as a result. They could join the Young Justice team to seek revenge against the Joker. Another idea is an OC who is related to an existing character in the Young Justice universe and is lured into the Joker's chaotic world. For example, a relative of Robin who the Joker tries to corrupt.
One idea could be an OC Green Lantern from a different planet arriving on Earth and having to adjust to the Young Justice team's way of doing things. They might have unique powers related to their home planet's culture that add new elements to the team's battles.
One idea could be that the OC is a new meta - human with a unique power that Batman is initially suspicious of. Maybe the OC's power is related to mind - reading, and they accidentally read Batman's thoughts during a mission, leading to some tense and comical moments as Batman tries to keep his secrets while also using the OC's power to their advantage. Another plot could involve the OC being from a different dimension and Batman has to help them adapt to Earth - 16 (the Young Justice universe) while also dealing with the threat that the OC's arrival may have brought. Or perhaps the OC has a connection to an old enemy of Batman's, and they must work together to uncover the mystery behind it.
One idea could be that the male OC clone discovers he has unique powers not shared by the original he was cloned from. For example, he might be able to manipulate energy in a way that surprises everyone. Another plot could involve the clone trying to find his own identity separate from the expectations placed on him because of his origin. He could struggle with whether to follow in the footsteps of the original or forge his own path.
Another idea is that the OC is a non - magic user who gets caught in a magical conflict that Zatanna is involved in. The OC has to rely on their wits and physical skills while Zatanna uses her magic. Their relationship could grow as they learn from each other's strengths and weaknesses. For example, the OC might teach Zatanna some street - smart tactics, and Zatanna could introduce the OC to the world of magic.
A possible plot is that the OC is a new recruit to the Young Justice team. Miss Martian is assigned to train the OC. At first, they don't get along because the OC is headstrong and doesn't like taking orders. But as they face various challenges together, like fighting against a powerful enemy that targets the team's weaknesses, they start to understand each other better. The OC could also have a secret past that Miss Martian helps uncover, which deepens their bond.