One plot idea could be an OC who is a scientist during World War II and teams up with Captain America. They could work on some top - secret projects together. Another is an OC who is a foreign agent sent to assess Captain America's abilities and ends up becoming his ally. Maybe an OC from the future who travels back in time to help Captain America prevent a major catastrophe that wasn't in the original timeline.
There could be an OC who is a journalist assigned to cover Captain America's story. Through their reporting, they get closer to him and end up involved in his adventures. Or an OC who has a special power related to time or space and uses it to assist Captain America in his battles. Also, an OC who is a street - smart kid from Brooklyn that Captain America takes under his wing and trains to be a hero in their own right.
One idea could be an OC who is a scientist caught in the middle. They could be working on a project that both sides think will give them an edge. For example, the OC might be developing a new type of energy source that could power super - weapons. Another plot could involve an OC with the power to manipulate emotions. They try to use their power to calm the situation between the two factions but end up getting caught in the crossfire. A third idea is an OC who is a journalist trying to expose the real reasons behind the civil war, which are more complex than just the superhero registration act.
One plot idea could be that the male OC is a new recruit to the Avengers. He initially clashes with Captain America due to different combat styles. But as they face various threats together, they gradually learn from each other and form a deep friendship. The OC could have a special power that is crucial in a particular mission, and Captain America comes to respect his abilities.
One idea could be an OC who is a scientist that gets caught in the middle of the conflict between Captain America and the Winter Soldier. She has to use her knowledge to try and stop the chaos while also dealing with her own secrets. Another could be an OC who is a long - lost friend of Bucky from before he became the Winter Soldier. This OC tries to bring back Bucky's memories. A third idea is an OC who is a new recruit in SHIELD and idolizes Captain America. He gets involved in the events and has to grow up fast to face the challenges.
Another idea is that there's a villain who can manipulate time and space. He sends Captain America to the Naruto world during a crucial time in Naruto's story, like right before a big battle. Captain America's leadership and battle experience help Naruto and his friends come up with a better strategy. And in the process, they learn from each other's values and fighting styles.
One idea could be inserting yourself as a new recruit in the Howling Commandos. You could have a special skill, like being an expert in decoding enemy messages. Then, you get to interact with Captain America and the team, facing challenges together and forging strong friendships. Another plot could be that you are a scientist in the same era as Steve Rogers. You accidentally discover a new element that could enhance the super - soldier serum. This draws the attention of both Captain America and the bad guys, leading to a race to protect or steal your discovery.
A plot could involve an alternate universe where Bucky was never captured by Hydra. He and Steve continue their adventures together, fighting different villains. Or perhaps a story where the Winter Soldier is sent on a mission to assassinate Steve, but at the last moment, his true self starts to break through and he has to fight against his programming to save Steve.
One idea could be a crossover where Batman and Captain America team up to take on a common enemy like a powerful alien threat. They could combine their unique skills, with Batman's detective skills and gadgets and Captain America's combat expertise and leadership.
Maybe they get stuck in an alternate universe where they are the only superheroes. They then have to figure out how to get back while also protecting this new world from the villains there. In this situation, they might learn more about each other's values and become closer friends than before.
Well, perhaps the child in the fanfiction is born with a unique power that combines Captain America's leadership qualities on a genetic level with Black Widow's ability to adapt to any situation. This power makes the child a target for villains who want to use it for their own evil plans. The story could revolve around the child learning to control this power and use it for good, all while dealing with the legacy of their famous parents.
Perhaps in an alternate universe where they are not just teammates but also childhood friends. As they grow up, their relationship deepens and a kiss between them could be the start of a new romantic chapter. They might share this kiss during a quiet moment in a park they used to play in as kids.