Violet started off as a shy and somewhat insecure girl. She was hesitant to use her powers, especially in public. But as the story progressed, she had to step up to protect her family. This led to her becoming more confident and assertive in using her powers, like when she created large force fields to shield her family from danger.
There could be a group of anti - superpowered people who kidnap Violet. They believe that superpowers are a threat to the normal world and they want to study Violet to find a way to nullify superpowers. They might be a secret organization that has been operating in the shadows, waiting for the right moment to strike at the superpowered community by targeting one of its youngest members.
Another story could be how Violet interacted with her family members. She might have had some really sweet moments with her younger brother, like protecting him in a dangerous situation using her powers. Also, her relationship with her parents was constantly evolving as they all had to deal with the fact that they were a family of superheroes.
Well, one possible plot could be that Violet is kidnapped by a villain who wants to use her powers for evil. Maybe this villain has some sort of device that can suppress her powers temporarily. The rest of the Incredibles family then has to go on a rescue mission. They could face various obstacles along the way, like traps set by the kidnapper. Mr. Incredible might use his strength to break through barriers, while Dash could use his speed to scout ahead and gather information.
The Avengers would likely have a range of reactions. Captain America would respect the Incredibles' sense of justice. And the Hulk might just be confused at first but then find it cool.
If the Avengers watched The Incredibles, it could be a very interesting scenario. The Hulk might get a bit jealous seeing Mr. Incredible's strength at first. Black Widow would notice how Mrs. Incredible manages to be a great mother and a superhero at the same time. Hawkeye would be interested in the archery skills of any character in the movie who might use a bow. And they all could learn something about teamwork from the family's dynamic in the movie.
No. Since it's a 'lemon' fanfic, it likely contains inappropriate content. 'The Incredibles' is a family - friendly franchise, and a 'lemon' fanfic would go against the intended audience and values of the original work.