The combination of powers. You get to see the superpowers of the X - Men, like Jean Grey's telekinesis and Cyclops' optic blasts, interact with the powers of the Avengers such as Thor's lightning and Captain America's super - strength. It makes for some really epic battle scenes.
One great 'xmen and avengers crossover fanfic' is 'The United Front'. It has an exciting plot where the X - Men and the Avengers have to team up against a common enemy from another dimension. The character interactions are really well - written, especially the banter between Wolverine and Iron Man.
One common theme is the exploration of power dynamics. When the X - Men cross over with other groups, like the Avengers or the Fantastic Four, there's always a comparison and contrast of their powers. For example, in a crossover with the Avengers, the mutants' powers might be seen as more unpredictable compared to the technology - based powers of some Avengers.
There's also 'X - Men and the Fantastic Four: A Mutant Alliance'. In this fanfiction, the X - Men team up with the Fantastic Four. It delves into how the two groups, with their different powers and personalities, work together. There are some really fun moments as they try to figure out how to combine their abilities to face various threats.
There's a fanfic called 'X - Avenger Team - Up'. It's a shorter but very engaging read. It focuses on a specific mission where a small group of X - Men and Avengers have to work together. The dialogue in it is really well - written, making the characters feel very true to their original versions. It shows how their different personalities can either clash or complement each other during the mission.
Some xmen fanfic stories center around alternate universes. In one such fanfic, the X - Men could be in a world where mutants are the dominant species and humans are the ones being persecuted. This would completely reverse the normal dynamic and force the X - Men to make different choices and face new moral dilemmas.
The ability to reimagine character relationships is also unique. Characters who might not have interacted in their original shows can form new alliances or rivalries in smallville crossover fanfiction. For instance, a character from Smallville could have a completely different relationship with a character from 'Supergirl' in a crossover. This gives fans a chance to see their favorite characters in new lights and explore different emotional arcs.
I really like 'Crossroads of Krypton and the Hunting Life'. In this fanfiction, the writers did an amazing job of bringing in the mythology of Smallville and Supernatural. Dean and Sam Winchester end up in Smallville and get involved with Clark's world. It's full of action and some really cool character moments. It shows how the different powers and skills of the characters from both shows can work together or clash in interesting situations.
I really liked a fanfic called 'Power Convergence'. In this story, the Charmed Ones end up in Smallville and they have to figure out how to get back home. Along the way, they meet Clark and his friends. It's a great read because it shows how the different power dynamics from each show would play out when the two worlds collide.
The X - Men's teleportation abilities, like Nightcrawler's, could play a big role in a crossover. He could teleport around Smallville, which would be a new and strange experience for the Smallville residents. And in return, the advanced technology in Smallville could potentially be used to enhance the X - Men's teleportation technology, allowing for longer - range jumps or more precise landings.