Maybe Korra travels back in time and meets the first Avatar. This encounter could lead to her learning ancient bending techniques directly from the source. She might also get involved in the political and social issues of that era, and her modern - day ideas could cause a stir. She could try to change the way the Avatar was perceived in the past, which would then have a ripple effect on her own time.
One possible plot could be Korra going back in time to prevent a great disaster that she has knowledge of in her own time. For example, she might go back to stop the start of a war that had long - lasting negative impacts on the world. She could use her bending skills in new and unexpected ways in the past, as the technology and bending styles of that time might be different.
In a 'Korra travels back in time fanfiction', it could be that Korra goes back to a time when bending was just emerging. She has to hide her advanced bending abilities at first. She then starts to teach the early benders some of the more refined forms she knows. This changes the course of bending history, and when she returns to her own time, she finds that bending has evolved in a completely different way.
Korra could meet the founders of the different bending disciplines. She could meet the first water benders and learn about the purest form of water bending. This would not only enhance her own skills but also give her a deeper connection to her water - bending heritage.
One possible plot could be that Esme travels back to a time when she was about to make a crucial life decision. For example, she might go back to the moment before she met her significant other. In the past, she could then have the chance to see things from a different perspective. Maybe she realizes that the decision she made back then was actually the best one, or she might find out new things about herself or the people around her that she didn't know before, which could lead to a whole new set of adventures and self - discovery in the past and ultimately change her view of her present life.
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 possible plot could be Ianto Jones going back in time to prevent a major disaster in Torchwood's history. Maybe he travels back to the time before the Cardiff Rift opened in such a large and dangerous way. He could use his knowledge from the future to stop an alien invasion that was the root cause of the rift's instability.
Perhaps in the 'ichigo travels back in time bleach fanfiction', Ichigo travels back to the time when the Soul Society was in a more fragile state. He could use his knowledge from the future to help strengthen the Soul Society against upcoming threats, like Aizen's plans. He might train the younger versions of the Soul Reapers and form new alliances that would change the future battles.
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.
One possible plot twist could be that they get back together due to a common enemy. Maybe a new threat emerges in their world and they realize that they work better as a team when they are together. So they put aside their past differences and start to re - kindle their relationship.