One idea could be a new character joining the Avengers. For example, a young mutant with the power to control time. This character could accidentally disrupt the timeline while trying to prove themselves to the team, leading to all sorts of chaos and adventures as the Avengers try to fix it.
A plot could involve the Avengers traveling to different dimensions through the disks and having to team up with alternate versions of themselves to defeat a common enemy. This would bring in a lot of interesting character interactions and new power combinations.
One idea could be exploring what if a minor character from the movie got the Infinity Stones instead. For example, a random Asgardian warrior. They might use the power in a completely different way, perhaps trying to restore Asgard rather than the more universal aims Thanos had.
One idea could be that the Avengers discover a new form of happiness that is not based on victory but on self - discovery. They each go on a journey to find what truly makes them happy outside of their superhero personas.
One idea could be to cross the Avengers with the characters from Harry Potter. Imagine Iron Man trying to figure out how to use a magic wand, or Thor comparing his hammer to a magic broomstick. Another idea is to crossover with the Star Wars universe. Captain America leading the Rebel Alliance against the Empire would be really cool.
One idea could be a crossover where Naruto gains Saiyan powers and teams up with the Avengers. He could use his newfound Saiyan strength and speed, combined with his ninja skills, to take on powerful villains. For example, against Thanos, Naruto could use his Rasengan enhanced with Saiyan ki energy.
One idea could be a crossover where the Avengers end up in the wizarding world of Harry Potter. They might be confused by the magic at first but then start to learn and adapt. For example, Iron Man could try to figure out how to incorporate magic into his tech. Another idea is that Harry Potter and his friends are brought to the Avengers' universe and they help the Avengers fight a new kind of threat that has both magical and non - magical aspects. Maybe Voldemort somehow teams up with a supervillain from the Avengers world.
You could also write a fan fiction where the Avengers use time travel in a different way. Instead of going back to collect the Stones, they go back to stop Thanos from ever getting the idea of the Snap. This would involve changing key events in Thanos' past, like preventing him from meeting Gamora or finding out about the Infinity Stones.
Well, a plot could revolve around Luffy as a girl having to deal with the expectations of femininity in different islands they visit. Some islands might have strict gender roles, and she has to find a way to balance being true to herself as a fearless pirate while also navigating these cultural differences. And perhaps her crew helps her in different ways to overcome these obstacles.
Well, a plot could involve Naruto being initially ostracized in the village because of his deafness. But then, he proves his worth by using his unique perspective. Since he can't hear, he becomes extremely observant of body language. This helps him in battles and also in understanding the true feelings of people around him. He could also form a special bond with a character who is also an outcast, perhaps someone with a disability of their own, and together they change the perception of the village towards those with differences.
A possible plot is that Naruto's blindness is a result of a powerful enemy's attack. This forces him into a new world of darkness, but also reveals hidden powers within him. He could start to see things in a different way, not literally but metaphorically. His new - found understanding could lead him to be a better leader. For instance, he might be able to understand the pain of the oppressed in a more profound way, and thus fight for their rights more vehemently. His blindness could also be a way to bring out the best in his friends, as they rally around him to support and protect him.