One possible scenario could be that Quicksilver uses his super - speed to save an Avenger from a sudden attack. His speed would be a great asset to the Avengers in a fight. Maybe he teams up with Scarlet Witch, his sister, who is also involved with the Avengers in some storylines.
He could introduce new combat techniques to the Avengers. Since he moves at super - speed, he might have ways of fighting that the Avengers haven't seen before. For example, he could create a mini - tornado by running in circles really fast around an enemy.
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.
Quicksilver plays a crucial role in X - Men fanfiction. His speed makes him a very dynamic character. He can be used to create exciting action scenes, like quickly rescuing his fellow mutants from dangerous situations. He can also serve as a plot device, for example, if he discovers a secret about the X - Men's enemies because of his ability to move around unnoticed.
Quicksilver in X - Men fanfiction often has his speed - related powers explored in unique ways. Writers might focus on his relationships with other mutants, like how his super - speed affects his interactions with Wolverine or Storm. His backstory can also be expanded upon, perhaps delving deeper into his family history and how it influenced his character in the fan - created stories.
His powers could also be used for reconnaissance. Quicksilver could zip around and gather intel on Ultron's lair or his next move. This information would be crucial for the X - Men and the Avengers to plan their counter - attacks. He might find out about new types of Ultron drones being developed or a hidden weapon that Ultron plans to use against them.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of X - Men fanfictions, including those focused on Quicksilver and Wanda. Just use the search function and type in relevant keywords.
Another common one is the idea of them teaming up with other X - Men characters in unique ways. For example, they could go on a special mission where Quicksilver's speed and Wanda's powers are crucial for the success of the mission. It often involves a lot of action and adventure.
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.
Quicksilver dies in a rather tragic and unexpected way. He sacrifices himself to protect others during a major battle, getting caught in a lethal situation.
First, know your characters well. Read up on the Avengers and X - Men comics, movies, etc. to understand their powers, personalities, and backstories. For example, if you're writing about Iron Man and Cyclops, you need to know how their different leadership styles might interact. Second, come up with an interesting plot. It could be a new villain that forces them to team up, or a conflict within the combined group. Third, don't be afraid to add your own twists to the story. Maybe give a minor character a major role.