Cooperation is a frequent theme as well. Since crossovers usually involve different groups coming together, they have to learn to cooperate. In fanfictions where the X - Men cross with other powerful entities, they need to find common ground and work together despite their differences.
Power exploration is a big theme. Fem Harry has her own magical powers, and in the X - Men world, she has to figure out how they interact with the mutant powers. Also, acceptance is a theme. The X - Men are all about acceptance of differences, and Fem Harry has to find her place among them, whether it's being accepted as a non - mutant but still powerful being or finding a way to contribute to their cause. There's often a theme of fighting against prejudice too, as both she and the mutants face different forms of it in their respective worlds.
A sense of belonging is another big theme. The reader, who may feel like an outsider in the real world, finds a place where they belong among the mutants. There are also themes related to fighting for justice, just like the X - Men do in the original stories.
Friendship - turned - love is also very common. Characters who start as friends, like Jubilee and Dazzler, gradually develop deeper feelings for each other. It shows how their shared experiences as mutants bring them closer on an emotional level.
One common theme is speed. Given Pietro's super - speed ability, many fanfictions explore the limits and implications of his speed. Another theme is family, as his relationship with his sister Wanda is often a central part of the stories.
Well, identity is a big theme. Rogue often has to figure out who she is as a mutant and as a person in these fanfictions. There's also the theme of acceptance, both self - acceptance and acceptance from the X - Men community. Some fanfictions show Rogue trying to find her place within the team or among mutants in general. Additionally, adventure and fighting against villains are also common themes as they are in the original X - Men stories.
A common theme is self - discovery. Blink is often portrayed as learning more about her powers and herself. Another theme is friendship, like her relationships with other X - Men members. And there's also the theme of survival, as mutants in the X - Men universe are constantly facing threats.
A major theme is teamwork. In crossovers like Naruto x One Piece, Naruto has to work with the Straw Hat Pirates. They both value friendship and loyalty, but they have different ways of achieving their goals. Also, identity is a theme. When Naruto crosses into the DC Universe, he has to figure out how his ninja identity fits in with the superheroes and villains there. He may struggle with being an outsider at first.
One common theme is redemption. Often, the OC has a troubled past or has made mistakes, and through their interactions with Logan, they seek redemption. For example, in many stories, the OC might have been involved with the wrong side initially but then changes for the better.
One common theme is Pyro's struggle with his powers. In many fanfictions, he has to deal with the fear of losing control over his pyrokinesis, which can be a source of internal conflict. Another theme is his relationships within the X - Men team. Some stories focus on his friendships or rivalries with other members like Wolverine or Storm.
One common theme is self - discovery. The little sister often has to figure out her powers and her place in the X - Men world. For example, she might start off not knowing she has powers at all and then slowly realize what she can do.