There's a fanfiction where Storm's weather - controlling abilities are crucial in an Avengers - level threat. The X - Men and Avengers have to work together to stop a global weather - based disaster. In some crossovers, Cyclops' optic blasts are combined with Hawkeye's archery skills in a strategic way. They create a unique combat style that helps the combined team take on enemies. Also, Rogue's power - absorbing ability can lead to some really interesting interactions when she absorbs the powers of various Avengers members.
A really cool X - Men and Avengers crossover fanfiction might involve Professor X using his telepathy to link the minds of the Avengers and X - Men, creating a super - team with combined powers and strategies. This could lead to some great character development as heroes from different universes learn to work together. Another concept could be a time - travel story where the X - Men and Avengers have to go back in time to prevent a mutant - hating villain from changing history in a way that would destroy both their worlds.
One great example could be a story where Flash uses his super speed to help the Avengers in a battle against a time - traveling villain. Maybe he's able to disrupt the villain's time - based powers, giving the Avengers an edge. Another could be a fanfiction where Flash has to adapt to the Avengers' more teamwork - oriented style of fighting, which is different from his solo adventures in his own universe.
One great example could be a story where Jack Frost from Rotg teams up with the Avengers. Maybe he uses his ice powers to help them in a battle against a common enemy like Loki who has somehow gained control over a powerful ice - related artifact. Jack could freeze Loki's magic for a short time, giving the Avengers an advantage.
One great example could be a story where Batman's detective skills are put to the test in an Avengers - style global threat situation. Maybe he teams up with Iron Man to analyze some high - tech alien weaponry. Another could involve Nightwing and Hawkeye having an archery - based competition that turns into a team - up against a group of villains. And there's also the idea of Alfred and Jarvis having a conversation about taking care of their respective heroes, which could be both humorous and heartwarming.
One great example could be a story where Buffy Summers finds herself in the Avengers' world. Maybe she teams up with Black Widow, sharing their combat skills and female empowerment stories. Another could involve the Avengers having to deal with a vampire threat that only Buffy has the expertise to handle.
A genetic experiment gone wrong could also be a great plot for the crossover. A mad scientist tries to combine mutant and super - soldier DNA. This creates a new breed of dangerous creatures. The X - Men, with their knowledge of mutants, and the Avengers, with their combat skills and high - tech resources, must work together to contain the threat. Jean Grey's telepathic powers could be crucial in finding the source of the experiment, while Iron Man uses his technology to develop a way to reverse the genetic changes.
There are fanfictions where Quicksilver's relationship with a particular X - Man is explored in a crossover setting. For instance, his interactions with Rogue could be really interesting. Since he's so fast, he could potentially help her control her power in new ways. Maybe he could find a way to transfer the absorbed energy from her before it becomes too much for her to handle.
A cool plot could be that a new, extremely powerful mutant emerges who has the ability to control all forms of energy. This mutant's powers are so great that they start to disrupt the fabric of reality. The Avengers and the X - Men both realize that this mutant needs to be controlled or taught to manage their powers. However, different factions within both groups have different ideas on how to approach the situation. Some want to be more forceful, while others believe in a more diplomatic approach. This leads to internal conflicts within the combined group as they also battle external threats caused by the mutant's out - of - control powers.
One possible scenario could be that Quicksilver uses his super - speed to outmaneuver Ultron's attacks in the crossover. Maybe he teams up with both the X - Men and the Avengers, bringing his unique skills to the fight. For example, he could quickly disrupt Ultron's robotic minions or even steal important components from Ultron himself while the other heroes engage in direct combat.
One idea could be that the Avengers are called upon to help in the Pacific Rim universe when a Kaiju threat becomes too great for the Jaeger pilots alone. They could use their unique powers to assist in battles. For example, Thor could use his lightning to power up a Jaeger's weapons system. Another idea is that some of the Avengers become Jaeger pilots themselves. Iron Man could use his tech knowledge to upgrade the Jaeger technology. And Hulk could be a great asset in the physical combat against the Kaiju.
One idea could be a battle against a common enemy that is too powerful for either the Avengers or the X - Men alone. For example, a powerful alien race that wants to enslave mutants and humans alike. The two groups would have to combine their unique powers and skills to defeat this enemy. Another plot could involve a misunderstanding between the two teams that leads to a brief skirmish before they realize they are on the same side. For instance, the Avengers might mistake the X - Men's actions as a threat to humanity when in fact they are trying to protect a mutant from a rogue government agency.