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.
The X-Men and Avengers are connected in the comics through shared villains, joint missions, and character crossovers. For example, characters like Scarlet Witch have ties to both teams, influencing their interactions and storylines.
One good source could be Archive of Our Own (AO3). Just search for 'X Reader sad birthday' on it and you'll find a variety of works. Some might involve a character forgetting the reader's birthday, leading to a sad and angsty scenario.
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 great 'bnha x avengers fanfic' is 'Heroes United'. It combines the unique powers and characters from both universes in a really interesting way. The story has an engaging plot where the heroes from BNHA and the Avengers have to team up to face a common, powerful enemy. The character interactions are well - written, especially when Deku meets Spider - Man. They exchange ideas about responsibility and power, which is really cool.
One common theme is self - discovery. The reader character often has to figure out their place in the world of the Avengers and also discover their own strengths and weaknesses. Another theme is friendship. The reader forms bonds with the Avengers members, which can be really heartwarming.
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.