One interesting plot idea could be that in the alternate timeline, Tony Stark never becomes Iron Man. Instead, he devotes his life to clean energy research and Pepper Potts takes on a more superhero - like role, using Stark tech to fight crime. Another idea is that the Avengers lose the Battle of New York in this timeline, which leads to a dystopian world where the Chitauri rule, and the remaining heroes have to form an underground resistance.
An exciting plot idea for an Avengers alternate timeline fanfiction might be that the Infinity Stones are discovered and used in different ways. For example, instead of Thanos collecting them, a group of benevolent beings from another dimension use the stones to create a utopia on Earth. But this utopia has some unforeseen consequences. The Avengers then have to decide whether to support this new world order or try to return things to the way they were, which causes a rift within the team.
Well, a plot idea could be that in the alternate timeline, Thor lands on Earth as a child. He grows up among humans, learning their ways and values. When the time comes for the big threats, he has a different perspective on how to handle things. Maybe he tries to use diplomacy more than brute force at first. Also, in this timeline, Loki could be a hero instead of a villain. He could have been influenced by the kindness of the humans he met early on.
Another idea could be that all the snapped heroes come back with new powers. This would create a whole new set of challenges for the Avengers as they try to integrate these newly powered heroes into their fight against Thanos. It would also make for some really exciting battle scenes.
In an alternate timeline, Steve Rogers and Tony Stark might be closer friends from the start. Maybe they met during a different event and bonded over a shared love for some old - fashioned values. Their relationship could be less strained, which would also affect how the Avengers as a whole operate. Without their initial bickering, the team could be more united earlier on.
One interesting plot twist could be if Harry was sorted into Slytherin instead of Gryffindor. This would completely change his relationships and the way he is perceived in the wizarding world. Another could be if Voldemort had a change of heart early on and decided to abandon his dark ways. It would be a huge shift in the entire story's dynamic.
Some interesting plots in RWBY alternate fanfiction could involve an alternate reality where the Dust doesn't exist. This would completely change the way combat and technology work in Remnant. Hunters and Huntresses would have to rely more on their physical abilities and semblances. Or there could be a story where Team RWBY is formed much earlier in their lives, like as children, and they grow up together facing different challenges than in the original story. There could also be a fanfic where the world of Remnant is invaded by an outside force from another dimension, and the RWBY characters have to adapt quickly to this new threat.
A really cool plot idea could be that the Avengers are watching Endgame in a sort of 'alternate reality cinema' where the events in the movie start to bleed into their real world. So they have to stop the movie from fully playing out to prevent chaos in their own universe. This would involve a lot of action and strategic thinking as they try to stop things like Thanos from emerging from the screen while also trying to understand the significance of what they're seeing in the movie.
Perhaps the Avengers mistake one of the Horsemen for a new super - villain. As they engage in battle, they soon realize that the Horsemen is actually after a powerful artifact that a real villain in the Avengers' world has obtained. So they form an uneasy alliance to retrieve the artifact.
Maybe in the fanfiction, the multiverse is collapsing and the Avengers of different universes are brought together by a mysterious force. They find out that an experiment gone wrong in one of the universes has caused this. So they have to travel through different universes, each with its own unique versions of the Avengers and villains. Along the way, they discover new powers and abilities that they can use to try and reverse the damage and save the multiverse.
One interesting plot could be the Avengers facing a new, super - powerful villain made of an unbreakable steel - like substance. They have to figure out how to defeat it without their usual methods working.
One interesting plot could be the Avengers facing an ancient, all - powerful cosmic entity that threatens to destroy all of existence. They have to combine their powers in ways they never thought possible, like Iron Man's technology with Thor's magic.
One idea could be the Avengers facing off against a new, powerful villain who has the ability to turn their own powers against them. This would lead to some really intense battles and strategic thinking on the Avengers' part.