One common plot twist could be that the end, when traveling back in time, accidentally changes something that has a huge ripple effect on the future. For example, they might prevent an important event from happening that was crucial for the development of a certain technology or the rise of a key character. Another plot twist could be that the end realizes they are not actually in their own past but in an alternate timeline. This can lead to a whole new set of challenges as they try to figure out how to get back to their own timeline or if they should even try to change things in this new one.
A typical plot twist in 'end travels back in time' fanfiction is that the end gets stuck in a time loop while traveling back. They keep repeating the same period of time over and over, and each time they try different things to break free. Another interesting twist can be that the end finds out that someone they trusted in the future has actually been manipulating their time - travel all along. This revelation turns their whole mission on its head as they now have to figure out who to trust and what their real goals should be.
Well, often in such fanfictions, a plot twist is that the 'end' discovers that they are the cause of a future problem while traveling back in time. Maybe they were sent back to prevent something, but in the process of trying to do so, they end up doing the very things that led to the problem in the first place. Also, there could be a twist where the end meets a younger version of themselves and has to deal with their own naivete or inexperience from the past. It's like looking in a mirror but seeing a different person in a way.
Well, a really interesting plot twist might be that when Merlin travels back in time, he discovers that the future he thought he knew was all wrong. Maybe the events that led to Arthur's rise and fall were actually set in motion by a time - traveling sorcerer from even further in the future. He could also find that the people he thought were his allies in the past were actually working against him all along, which would completely change his view of history and his role in it.
Perhaps Tony travels back to a time before a key technology was developed in his world. He then has to figure out how to recreate that technology with the limited resources of the past. This could lead to some really interesting interactions with the scientists of that era. Also, he might accidentally introduce some future concepts that are far ahead of their time, which could cause a stir among the intellectual community. And if he changes the development of this technology too much, it could have a huge impact on the future he came from.
Well, a really interesting plot twist might be that when Rick travels back in time, he discovers that time is actually a loop. So all his actions in the past were already pre - determined and he was just fulfilling his part in the loop. This could lead to a whole existential crisis for Rick as he realizes he may not have as much control as he thought. Or perhaps he goes back and finds out that an enemy from the future has already been manipulating events in the past to try and stop Rick from ever becoming the genius he is.
Well, a really interesting plot twist in an Eren travels back in time fanfiction could be related to relationships. Say Eren goes back and realizes that his actions in the past have a huge impact on his relationships with his friends. Maybe he accidentally causes Mikasa to not be as attached to him as she was in the original timeline. Or he could find out that Armin was supposed to be the one with the time - traveling ability all along, and his interference messes up Armin's future plans. Also, what if he goes back and discovers that the real enemy wasn't the Titans but some other force that was using the Titans as a distraction, and his time - traveling journey is the only way to expose this truth.
A plot twist could be that Sakura travels back in time and realizes that the world she thought she knew was all a lie. The history books in her time were wrong. She could find that the origin of her magical powers was something very different from what she was taught. Also, she might go back to a time when there was a powerful artifact that was lost in her own time. However, when she tries to retrieve it, she discovers that it has a dark side that she didn't expect. This could lead to a moral dilemma for her, whether to keep it or leave it be.
One exciting plot twist could be Octavia traveling back in time and accidentally changing a key event that led to the creation of the Ark. This would completely rewrite the history of the 100. Another could be her meeting a younger version of herself and trying to guide her without revealing her true identity. It would create a lot of internal conflict for Octavia as she sees her younger, more naive self.
One common plot twist is Naruto changing the fate of certain characters who died in the original story. For example, he might save someone like Jiraiya from his encounter with Pain. Another could be Naruto influencing the political situation in the Hidden Leaf much earlier, perhaps preventing the Uchiha massacre by getting to the root of the problem between the Uchiha and the village leadership. Also, he could change the way ninja training is conducted in the past, leading to a stronger Hidden Leaf in the present he left.
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.
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 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.