I think Bakugo could be a character who time travels. He's extremely competitive and always wants to be the best. He might go back in time to outdo his rivals even more. For example, he could go back to his school days and show off his quirk in an even more impressive way. He might also go back to the time when he and Midoriya first had their conflict and handle it differently.
All Might might time travel in a fanfic. He could go back to his healthier days to relive his glory moments or to try and prevent his own decline. Maybe he wants to change something in his past that led to his current weakened state. He could also use the knowledge from the future to better train Midoriya from the very beginning.
Midoriya would be a likely candidate. He's always looking for ways to improve and become a better hero. Time travel could give him the chance to learn from past heroes directly, like All Might in his prime. He could also go back to understand more about One for All's past users and how to master the quirk faster.
There's also 'A Hero's Second Chance'. This fanfiction focuses on a character getting a second chance through time travel. It explores different relationships in the series in a new light. The author does a great job of creating suspense and making the readers wonder what will happen next.
Eleven could be a likely candidate. Given her powerful psychic abilities, she might accidentally or purposefully time travel. Her powers have always been a bit unpredictable, and time travel could be an extension of that. She has a strong connection to the Upside Down, so she might be sent back in time to learn more about its origin or how to stop it.
Izuku Midoriya is a likely candidate. His strong sense of justice and his journey to become the greatest hero make him a prime character for time - travel scenarios. He might travel back in time to gain more knowledge or to prevent certain tragedies. Another one could be All Might. His past is full of secrets and his influence on the hero world is huge. Time travel could be used to explore more of his backstory or to change some crucial events in his past.
I think Tyrion Lannister would be an interesting character to time travel in a fanfiction. He's very intelligent and cunning. Time travel could be his way to outwit his family and those who have wronged him. Arya Stark could also be a likely character. She has the skills of a faceless man. If she could time travel, she could use her skills to change the past, perhaps by assassinating key enemies before they cause harm. And of course, Melisandre. She has some sort of magic related to seeing the future. It's not a stretch to think she could find a way to time travel in a fanfiction and change the course of events in Westeros.
One popular trope is the 'fix - it' time travel. This is where a character goes back in time to fix a major event that went wrong in the original timeline, like preventing a hero's death. Another is the 'fish - out - of - water' trope. When a character travels to a different time period, they have to adapt to the new ways and rules. For example, if a modern - day hero travels back to the early days of quirks, they'd find a very different society. There's also the 'time - loop' trope, where a character is stuck repeating the same period of time until they figure out how to break the loop.
Well, it's also about the emotional aspect. Fans can create stories where characters get a second chance or make amends. This can be really heart - warming or heart - breaking depending on how the story is written. It gives a sense of control over a story that fans already love, and that's why it's so popular.
In time travel fanfictions of My Hero Academia, it could affect the storyline in many ways. If Deku could time travel, he might go back to tell All Might not to push himself so hard and avoid his injury. This would mean All Might could be a stronger symbol of peace for longer. Also, time travel could be used to expose hidden secrets of the villains earlier. For instance, if someone went back to the time when the League of Villains was forming, they could gather intel and prevent some of their attacks. This would disrupt the villains' plans and give the heroes an upper hand.
Batman himself is a likely candidate. Given his intelligence and determination, he might stumble upon a time - traveling device or technology while investigating some strange phenomenon. He would be driven by his need to protect Gotham, perhaps by preventing a future catastrophe that he has foreseen.
I think Fundy would be likely to time travel. He has a complex relationship with his family and the SMP. Time travel could be a means for him to understand his father better or change the way his family relationships developed. GeorgeNotFound could also be a candidate. He's often in the background but has a strong connection to Dream. Time travel might be his way of getting more involved in the SMP's events and helping Dream in a different way. Lastly, Niki could be a time traveler. She has been through a lot of changes on the SMP, and time travel could be her opportunity to go back and make the SMP a more inclusive and friendly place from the start, especially for those who have been marginalized.
I think Yamato could be a good choice too. His ability to control wood style could be really useful in the past. Maybe he could time - travel to help with the growth of the first trees in the ninja world or something like that. And his calm and collected nature would help him adapt to the new situation in the past.