One idea could be that she absorbs an unknown energy source which gives her new powers but also makes her a target. Enemies might try to steal or control this new power within her.
In the fanfic, she could absorb energy from a dying star. This super - charged energy might be too much for her to handle at first. She has to learn to gradually adapt to it, and in the process, discovers new ways to use her powers that she never thought of before.
A plot could be about an alternate universe where Captain Marvel is initially distrusted by the Avengers. She has to prove herself and in the process, they all learn more about each other's powers and pasts. This could lead to some great character development and new alliances within the team.
One idea could be a time - travel fanfic where Captain Marvel and Captain America team up in a different era. Maybe they end up in the 1920s and have to deal with a Hydra - like threat that's starting to form early. Another could be a fanfic where they swap powers for a day and have to learn to adapt to each other's abilities. For example, Captain America trying to control Captain Marvel's photon blasts and Captain Marvel having to rely on just her combat skills like Cap usually does.
One idea could be Captain Marvel bringing back some alien tech that the Avengers have to figure out how to use. It could lead to new powers for some of the members or a new way to defend Earth.
Another concept could be a time - travel fanfic. Black Widow somehow gets sent to a time when Captain Marvel was just starting out as a hero. Black Widow then has to train the younger Captain Marvel and help her unlock her full potential while also trying to find a way back to her own time.
One idea could be a story where Captain Marvel and Valkyrie team up to fight a new, powerful enemy that threatens the entire universe. They start off not getting along due to their different fighting styles and personalities, but as they face challenges together, they learn to respect and rely on each other.
A plot could involve Goku and Captain Marvel being on opposite sides of a moral dilemma. For example, Goku might be more focused on a pure battle for the sake of getting stronger, while Captain Marvel is more concerned with protecting the innocent. This conflict could lead to some intense battles between them at first, but then they discover a greater threat that makes them see eye - to - eye. Also, they could be in a story where they are both summoned to a strange new world and have to rely on each other to find a way back home. Maybe they find a powerful artifact there that has the power to change the balance of power in their respective universes.
One idea could be that Naruto and Captain Marvel are brought together by a powerful cosmic force. They have to combine their unique abilities, Naruto's ninja skills and Captain Marvel's superpowers, to defeat a common enemy that threatens both their worlds. For example, a powerful alien race that is draining chakra from Naruto's world and energy from Captain Marvel's universe.
It could be that Carol is in a situation where she has no choice but to absorb the energy beam. This might be part of an experiment gone wrong or an attack on her that she turns to her advantage. After absorbing it, she might struggle to control the new energy within her and has to go on a journey to master it. She could meet other characters who help or hinder her in this process.
Well, a cool plot could be reincarnating into the body of a Stark Industries employee. You then use your knowledge of future tech from your past life to revolutionize Stark's inventions even further. This could lead to new and improved Iron Man suits way before they were originally created in the Marvel timeline. Or, you could be reincarnated as an Asgardian commoner but with a deep knowledge of Earth's cultures. You could introduce things like rock music to Asgard, creating a whole new cultural exchange between the two realms.
One idea could be that Captain Marvel and Spider - Man team up to stop a powerful alien threat that's immune to most of Earth's defenses. They'd have to combine their unique powers. Captain Marvel's energy - based attacks and flight, along with Spider - Man's agility and web - slinging skills, would make for an exciting battle.