Another plot could involve Stark time - traveling to key moments in his own life. For instance, he travels back to when he first started Stark Industries and makes different decisions about the direction of the company, which then has a huge impact on the future of the world in terms of technology, superhero relations, and global politics.
Maybe Stark travels to the future and discovers a world where his technology has been misused to the extreme. He then returns to his own time determined to set safeguards to prevent such a future. He could start new research projects focused on ethical technology use.
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.
Maybe all the Starks, including Pepper and Morgan, travel back to the time when Howard Stark was starting out in business. They could help him with modern knowledge, and in the process, they might accidentally change some key events that lead to unforeseen consequences, like a new kind of Iron Man suit being created much earlier.
One idea could be Arya traveling back to the time before her family's downfall. She could use her skills to prevent certain events from happening, like Ned Stark's execution. Maybe she'd change the course of battles by secretly assassinating key enemies.
One plot idea could be that Jon and Sansa travel back to the time before their family's downfall. They could use their knowledge of future events to prevent Ned Stark's execution. For example, they might be able to expose Littlefinger's schemes earlier. Another idea is that they travel to a future time where the White Walkers have been defeated, but they find new threats emerging and have to figure out how to deal with them. They could also travel to different kingdoms in different eras and learn about different cultures and forms of governance, which could then help them better rule Winterfell and the North.
Well, perhaps Tony Stark time - travels during the Civil War to a moment when he first started developing Ultron. He then uses his future self's wisdom to avoid creating Ultron in the first place. This would change the entire dynamic of the Civil War as the destruction caused by Ultron was a major factor in the public's distrust of the Avengers. He could also time - travel to meet a younger version of Captain America and try to understand his point of view better from the start.
One idea could be that Tony Stark's daughter discovers a hidden time - travel device in her father's old workshop. She decides to use it to go back in time to prevent her father's death. Along the way, she meets younger versions of the Avengers and has to convince them to help her without revealing too much about the future.
One idea could be a story where Tony discovers a hidden diary of Howard's that reveals secrets about his early inventions and the true motives behind some of his actions. This could lead to Tony having a new perspective on his father and his own work.
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.
A possible plot for 'Haikyuu time travel fanfiction' is that Tsukishima travels back to his childhood when he first started to dislike volleyball. He could then understand why he developed that negative feeling and change his attitude from the start. This would lead to a much stronger Tsukishima in the present day. Another idea is that a team manager travels back in time to recruit a different set of players for the team, creating a completely different team dynamic. Maybe they could even bring back an old - school player who had unique skills that could revolutionize the team's playing style.
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.