It could be due to the lack of understanding of Captain Marvel's character. Her backstory is quite complex and different from some traditional superheroes. If a writer doesn't fully grasp it, they may choose not to include her in their fanfic. Also, the way she was introduced in the MCU might not have resonated as much with some fans as other characters, leading to less fanfic about her.
Another reason could be related to the existing fanfic communities and their trends. Some fanfic communities may have developed around certain groups of characters before Captain Marvel was introduced. Once those trends are set, it can be difficult for new characters like her to break in. So, she might be left out just because the community is already centered around other characters.
Fanfic writers often draw inspiration from the relationships between characters. Captain Marvel doesn't have as many pre - established and well - loved relationships within the superhero universe as some other characters. For example, the bromance between Thor and Hulk or the complex relationship between Batman and Joker in DC. Without these kinds of engaging relationships to build on, it might be less appealing for writers to include her in their fanfics.
She could meet a very smart science teacher who is intrigued by her powers and wants to study them scientifically.
Well, it's hard to say who the 'best' is as it depends on personal taste. But some popular authors in the fanfic community often include those who have a deep understanding of the characters. For example, 'MarvelFan45' has written some really engaging stories that explore the relationship between Captain Marvel and Captain America in different scenarios. Their writing style is very descriptive, making you feel like you're right there with the characters.
One common theme is self - discovery. Captain Marvel is often on a journey to understand more about her powers and her place in the universe. For example, in many fanfics she might go to a new planet and learn something new about herself through the experiences there.
In many Captain Marvel Billy fanfics, the relationship between Billy and the other characters in the Captain Marvel universe is well - developed. For example, his interactions with the Guardians of the Galaxy or other superheroes can add a lot of depth to the story. These fanfics can also be a great way to explore different storylines that might not be covered in the official comics or movies.
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.
One possible fanfic could be about Captain Marvel arriving just in time during the battle in Infinity War. She could use her powers to turn the tide against Thanos. Maybe she teams up with Iron Man and they combine their technological and super - powered might to take on Thanos' forces.
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.
In some fanfics, there could be a creative interpretation where Captain Marvel is made out to be Peter's mom, but this is not part of the official Marvel canon.