She could change many important events. Maybe she would prevent some tragedies from happening in the Star Wars universe. For example, she might be able to save some Jedi who were killed during Order 66.
If Ahsoka goes back in time in fanfiction, she might meet her former self. This could lead to some really interesting self - discovery moments. She could also use her knowledge of the future to train herself better, making her an even more powerful Jedi. She might also be able to influence the relationship between the Jedi and the Sith in a different way, potentially averting the great conflict that tore the galaxy apart.
Well, he could potentially change a lot of things. Maybe he would prevent some of the tragedies that happened in the original timeline. For example, he might stop the Uchiha massacre. He could also use his knowledge of future events and the power of the Juubi to make the ninja world a more peaceful place from the start.
Well, in such a fanfiction, the characters might try to change past events. For example, Naruto could prevent some of the early tragedies in his village. Maybe he'd stop the Nine - Tails attack by somehow convincing his father not to sacrifice himself. This would change the whole future of the village and the relationships between characters.
In fanfiction, if Harry goes back in time to the god, he might gain some extraordinary powers. Maybe the god would bestow upon him the ability to control magic in ways he never could before. It could also lead to him changing the course of history, for better or worse.
She might change the course of events in the past. For example, she could prevent some tragedies that happened to her family. Maybe she would use her advanced knowledge to help her father, Tony Stark, earlier in his life, which could potentially lead to a different future for the Avengers and the whole world.
He might change the outcome of some crucial events. For example, he could prevent the Red Wedding from happening, saving his family and allies. This would completely rewrite the story's future, leading to a different power structure in Westeros.
He could end up altering the entire history of the Gem war. Steven might try to find a way to end the war peacefully much earlier. He could convince the Diamonds to change their ways before things got as bad as they did in the original timeline. This would mean that many Gems who were corrupted in the original story might not be corrupted at all. And the Earth would probably be a very different place, with a more harmonious relationship between the Gems and humans.
Well, he could change a lot of things. Maybe he'd prevent some of the big battles or save some characters who died. For example, he might stop Frieza from destroying Planet Vegeta earlier. It would be a whole new timeline with different outcomes.
In this kind of fanfiction, Edward might try to change the past events that led to his and his brother's misfortunes. Maybe he'd prevent the failed human transmutation in the first place, saving Alphonse from losing his body.
Well, he would have a second chance at life. Since he was a baby, he could grow up with different relationships. He might form stronger bonds with his parents and be able to learn more about his family. Also, he could start training earlier and become an even more powerful ninja. With his knowledge from the future, he could also help the village in new ways, like coming up with better strategies against enemies.
Well, he could change a lot of things. Maybe he'd prevent some of the big battles or save some characters who died in the original timeline. For example, he might stop Frieza from destroying Planet Vegeta earlier. It would also be interesting to see how his Ultra Instinct powers interact with the past events and characters who haven't seen such power before.