Yes, there are many. For example, the storylines of characters like Scarlet Witch. Her story involves her complex origin, her powers which are both incredibly strong and at times difficult to control. It includes her relationships within the Avengers and how she has influenced major events in the Marvel Universe.
One popular theme is their teamwork. Writers like to show how the Marvel girls combine their different powers and skills to overcome challenges. For instance, in some fanfics, Black Widow's combat skills, Scarlet Witch's magic, and Captain Marvel's strength are all used together to defeat a powerful enemy.
Definitely. Some fanfics explore the backstories of the Marvel girls. How they became who they are, their struggles before joining the superhero world. These stories are often clean and can be really interesting as they give more depth to the characters without any inappropriate elements.
It's hard to give an exact number. There are a ton of Marvel characters that have been featured in various adaptations, but it changes over time and across different projects.
The X - Men might have mixed reactions. Professor Xavier would likely be intrigued by the potential for better mutant - human relations in the future. However, Wolverine might be skeptical and on guard, fearing that the future holds new threats to mutants. He's always been the more cynical of the group. The different reactions among the Marvel characters would add a lot of depth and interesting plot points to the fanfiction.
Definitely Loki. He's a fan favorite and can easily fit into various crossovers. His mischievous nature can add a lot of twists to a story. For example, if he were to cross paths with the Fantastic Four, he could play all sorts of mind games with Reed Richards while also being intrigued by Sue Storm's powers.
Marvel Comics is filled with amazing characters. For instance, there's Wolverine, who's known for his toughness and regenerative abilities. Then there's Doctor Strange, with his mastery of magic. And let's not forget about the Guardians of the Galaxy, a diverse and fun group.