Often, Dean will go back in time and accidentally change something small that has huge ripple effects on the future. Like he might save someone who was supposed to die, and then that person ends up causing a lot of chaos in the future that Dean has to fix. This creates a cycle of trying to set things right again. Another plot twist could be that when he goes back, he meets an alternate version of himself or his loved ones that are very different from what he knows, and he has to figure out how to deal with them.
One plot twist that shows up is that the reason Dean is sent back in time is not what it seems at first. Maybe it's not just a random time - travel accident, but a carefully planned move by a powerful entity. And this entity has its own motives that are slowly revealed as Dean tries to find his way back to his own time. There could also be a situation where Dean goes back in time and finds that the rules of hunting are very different in the past, and he has to adapt quickly to survive and also to achieve his goals of not messing up the future.
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.
One common plot twist could be that Naruko discovers she has the power to change not only her own fate but also the fate of the entire village. For example, she might prevent a major disaster that originally happened in the past. Another could be that she finds out a hidden truth about her family or a powerful jutsu that was lost in time. Maybe she realizes that a person she thought was an enemy in the present was actually a friend in the past and has to figure out how to reconcile that in the future.
Well, sometimes in these fanfictions, a plot twist might be that Sirius goes back in time and discovers a hidden truth about his family. Maybe he finds out that there was a secret alliance or a hidden enemy within the Black family that was influencing events all along. This could completely change his perception of his family's past and his place in it. Also, he could go back in time and end up being involved in a different kind of magic that was lost in his original time, like an ancient form of magic that has the power to either save or destroy the wizarding world.
One possible plot twist could be that Katniss goes back in time and prevents the Hunger Games from ever starting. Maybe she meets the people who first came up with the idea and manages to change their minds. Another could be that she goes back to a time before her father died and is able to save him, which would completely change her family's situation and her own personality development. A third plot twist might be that she goes back to a crucial moment in the Games and alters the outcome in a way that surprises everyone.
One plot idea could be Sam going back in time to prevent a major tragedy in his family's past. For example, he could try to stop the demon from killing Mary Winchester, which would change the entire course of his and Dean's lives. Another idea is that he goes back to a time when hunters were just starting to organize and he tries to influence the development of the hunting community for the better.
A lot of dean winchester time travel fanfiction also has the theme of brotherly love. Sam and Dean's relationship is central to the Supernatural series, and when Dean travels through time, it often affects Sam in some way. Whether it's to protect Sam from a past threat or to bring him back from a future where he's in danger, the bond between the brothers is always a key part of these stories.
Perhaps the biggest plot twist would be if Future Gohan's time - traveling somehow connects to a greater cosmic force or an ancient prophecy. His journey back in time could be part of a larger plan that he wasn't aware of. This could introduce new enemies or allies that are related to this cosmic plan. It might also mean that his actions in the past are not just about saving his own future, but about saving the entire universe from a much greater threat that was yet to be revealed.
One popular plot twist could be Killua going back in time and accidentally changing something that has a huge impact on his relationships. For example, he might prevent himself from meeting Gon in the first place, and then has to figure out how to get their friendship back on track. Another could be that he goes back to a time when a great evil was just starting, and he has to stop it before it gets out of hand, which completely changes the future he knew.
One possible plot twist could be that when they go back in time, they accidentally change something that has a huge impact on the present. For example, they might prevent the sorting hat from putting them in their original houses. This could lead to a completely different dynamic at Hogwarts, with different friendships and rivalries forming.
A really interesting plot twist could be that Steven goes back in time and discovers that the Diamonds had different motives than he originally thought. Maybe they were being influenced by some other force in the past, and by going back, he uncovers this mystery. Also, he could find out that some of the things he thought were his friends' ideas were actually planted by an outside source long ago. This would completely change his understanding of the relationships and history in the Steven Universe world.