Well, in the fanfiction, Itachi could go back in time and decide to train his younger self more rigorously. This would not only make him stronger but also change the way he approaches his future tasks. He might also try to influence Sasuke at an earlier age, guiding him in a different direction than in the original timeline. And he could befriend some characters earlier to build a stronger support network for the Uchiha clan.
It could be Danzo. In the original story, Danzo was a major factor in the Uchiha massacre. If Itachi goes back in time, Danzo would likely still be plotting against the Uchiha. His thirst for power and his extreme methods would put him at odds with Itachi's new attempts to save the clan.
She could meet her younger self. This would be an interesting encounter as she could offer advice and guidance to her younger version. Maybe she could help her younger self to be less afraid of her powers.
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.
One popular fanfiction with this plot is 'Time's Redemption'. In it, Hermione uses a powerful time - turning device to go back. She faces many challenges in the past, like avoiding detection by other characters while trying to figure out how to prevent Fred's death. It's a great read for those who love emotional and action - packed stories.
One common theme is redemption. When Dean goes back in time, he often tries to right the wrongs of the past, whether it's saving someone who died too soon or preventing a bad event from happening. Another theme is self - discovery. By being in a different time, he gets to see himself and his relationships in a new light.
Well, she might meet historical figures. For example, she could encounter Cleopatra and have an interesting conversation about ancient Egyptian politics and culture.
Maybe Yusei goes back in time to prevent a great disaster that happened in the past. He could use his knowledge from the future to change certain events and save lives.
Well, it could be that Sonic goes back in time because Shadow is in a dire situation that only Sonic can prevent. This could be due to a threat from a powerful villain that managed to overpower Shadow in the past. Sonic, being the hero he is, decides to take the risk of time travel. He might have to use some sort of time - traveling device or power. Once in the past, he'll need to quickly figure out how to stop the threat before it's too late. This fanfiction idea is really cool as it combines the action - packed nature of Sonic's world with the concept of time travel.