What are some interesting plot ideas for 'Haikyuu time travel fanfiction'?

One idea could be Yoda traveling back in time to train Anakin Skywalker differently, thus preventing his fall to the dark side. Maybe he goes back to the very beginning of the Jedi Order to gain more knowledge about the Force and bring it back to his own time.

One idea could be Shinji traveling back in time to prevent the Second Impact. He might try to change the actions of his father that led to it. Another could be Asuka traveling to a future where the Evangelions have been completely forgotten and she has to figure out how to get back to her own time.

Another plot could be a character from the future coming back to the present in Shameless. They could be trying to stop a future disaster that is somehow linked to the Gallagher family. This would involve a lot of mystery and intrigue as they try to figure out what the future event is and how to prevent it while dealing with the chaos of the present - day Gallagher family.

One idea could be Goten traveling back to the Saiyan - Saiyan war era. He could end up changing some small events that have big impacts on the future, like uniting some Saiyan clans earlier. This would create a whole new timeline where relationships between characters are different.

Maybe a character travels forward in time and sees a dystopian version of the ACOTAR world. They then have to go back and try to prevent the events that led to that future. They could face many challenges along the way, like not being believed or having to work against powerful forces who benefit from the future they saw. It would be a race against time to save their world.

One idea could be a modern-day character traveling back in time to the Hakuoki era and getting involved in the political intrigue. They could use their modern knowledge to try and change the course of events. Another plot could involve a character from the Hakuoki world traveling to the future and being shocked by the technological advancements. Maybe they struggle to adapt to the new world but also find new ways to bring back knowledge to their own time.

Perhaps Rex travels to a time where dinosaurs and humans co - exist. He has to figure out how this is possible and if it's a threat to the future. Or he could go back to the time of the Renaissance and become an apprentice to a famous artist, using his modern perspective to influence the art world in ways that have a ripple effect through time.

One idea could be that Tony Stark travels back in time to prevent the creation of certain dangerous technologies that later cause chaos in his timeline. He could use his genius to subtly alter the course of scientific development.

One idea could be that the Avengers go back in time to stop Thanos from ever getting the Infinity Stones in the first place. They might have to deal with different versions of themselves and the challenges of changing the past without ruining the future.

One idea could be Tsunade traveling back to the time when the Hidden Leaf was first founded. She could use her medical and combat skills to help the early settlers deal with diseases and threats from other villages. Another plot could be her going back to the time of the Third Great Ninja War and changing the fates of some of the fallen ninjas with her knowledge of future events.