What are some interesting plot ideas for an httyd time travel fanfic?

One idea could be Hiccup traveling back in time to the era when dragons first arrived in Berk. He could witness how the initial interactions between humans and dragons began and use his modern - day knowledge to try and improve relations even earlier. Another could be Toothless accidentally activating a time - travel device and taking Hiccup to a future where dragons are extinct, making them strive to find a way to prevent such a future.

One idea could be Batman traveling back to the time when Gotham was first founded. He could try to prevent the seeds of corruption from being sown. Another plot could be him traveling to a future Gotham that has been completely overrun by villains and he has to find a way to change that future by altering events in the past. Or perhaps he travels to different time periods to gather knowledge and technology to better fight crime in his own time.

A cool plot could be that a villain from the future uses time travel to go back and change the past in order to gain ultimate power in the Arrow universe. The heroes then have to figure out a way to reverse the changes and stop the villain. This could involve a lot of action scenes as they race against time to save their world from this altered timeline.

A cool plot for a Pokemon time travel fanfic might be that a Pokemon researcher travels back in time to study ancient Pokemon species that are now extinct. Along the way, they encounter problems like not being able to use modern technology to catch or study the Pokemon. They might have to rely on the knowledge of the people in that era. Also, a trainer could travel through time to meet their ancestors who were also Pokemon trainers and learn about their family's history in the Pokemon world.

Maybe a character from the future RWBY world travels back to the time when the Huntsman academies were first founded. They could introduce new fighting techniques or ideas that were developed in their time, which would have a huge impact on how the early Hunters and Huntresses are trained.

One idea could be that Luffy travels back to the time when Gol D. Roger was still alive. He could meet the Pirate King and learn some of his secrets. Maybe Roger gives him a hint about the One Piece that changes Luffy's understanding of his journey.

One idea could be that the characters from HTTYD find a strange portal that leads them to the Pokemon world. There, they have to learn how to catch and train Pokemon to find their way back home. Hiccup, being the curious and inventive type, might try to combine the technology of Berk with Pokemon training methods.

One idea could be that the time travel orb sends Naruto to a crucial point in the past where he can prevent a major tragedy. For example, he might be able to stop the Uchiha massacre, which would change the entire future of the ninja world. This would lead to different alliances and power dynamics.

One idea could be that Batman Beyond travels back to the time of the original Batman and has to team up with him to stop a villain who has also time - traveled and is trying to change history for his own evil gains.

Well, perhaps a group of students time travel to a future where they see the consequences of not assassinating Koro - sensei in time. This could give them new motivation and strategies when they return to their own time. Or, what if Koro - sensei time travels to different points in the students' lives and helps them in ways that are not related to assassination, like helping a student deal with a family issue in the past.