Well, it can change the whole course of events. For example, if a character travels back in time and warns Frodo about a particular danger he'll face, it could lead to a completely different outcome for the quest. Maybe Frodo would be better prepared and not get as injured or lost along the way.
Time travel can also introduce new relationships. Imagine a time - traveler from our world who falls in love with an elf in Middle - earth. This would create a whole new dynamic not present in the original story. It could also lead to changes in the political and social structure of Middle - earth as the time - traveler might have different ideas and values. Moreover, it could affect the power balance. If the time - traveler helps a certain side gain an advantage through knowledge from the future, it would shift the power struggle in the War of the Ring in unexpected ways.
In some fanfictions, time travel allows for the resurrection of characters who died in the original story. This has a huge impact on the storyline as it changes the emotional landscape. For instance, if Boromir were brought back to life through time - travel shenanigans, his presence could boost the morale of Gondor and change the way battles are fought. It also might lead to different alliances and rivalries as the resurrected character has a second chance at life and may act differently this time around.
It can make the storyline more complex and full of possibilities. When Harry time - travels, he might accidentally create a time paradox. This means that his actions in the past could have unforeseen consequences in the present. For instance, if he saves someone who was supposed to die, it could change the entire course of the war against Voldemort. Sometimes, time travel allows for characters to gain new powers or knowledge from the past, which they then use to change the future for the better or worse.
Time travel can completely reshape the canon storyline. For instance, if Harry goes back and saves Sirius, it changes the emotional state of Harry in later years. He would have a strong mentor figure by his side, which could lead to him being more confident and making different decisions. Also, if he stops Voldemort's Horcrux creation, the entire battle against Voldemort would be very different. There might not be a need for a long - drawn - out war, and many lives could be saved.
It can completely change the storyline. If Sasuke travels back, he can make different choices that alter the fates of many characters. For Naruko, it could mean she has a stronger ally earlier on. For example, if he goes back to their academy days, he could support her against the bullies, which would boost her confidence and change her development path. This would also affect how she approaches her ninja training and her goals.
Time travel in Dragon Ball Z fanfiction often creates a whole new set of possibilities. It might allow characters to meet their past or future selves. If a character like Trunks travels back in time again for some reason, he could end up changing things he didn't mean to. Maybe he could accidentally prevent Gohan from reaching a certain level of power, which would then have a domino effect on all the battles and relationships in the story. It's a great device to explore different 'what - if' scenarios in the Dragon Ball Z universe.
It can completely change it. For instance, if a character travels back in time to Mortis, they might prevent the death of the Father, which could have a huge impact on the balance of the Force not just on Mortis but throughout the galaxy. This could lead to a different future where the Sith may not have as much power as they did in the original timeline.
Time travel in a Game of Thrones fanfiction can have a huge impact on the storyline. If a character travels forward in time, they could bring back knowledge of future events and try to prevent disasters. Or if they travel back, they might accidentally change things that were meant to happen. This could lead to different characters rising to power or falling from grace. For example, if a time traveler influenced Tyrion's trial, the outcome could change his entire future and the future of the Lannisters.
The time travel fanfictions about Team STRQ can also fill in gaps in the canon. There could be aspects of the team's past that the show didn't fully explore. Through time travel, the fanfic can go back and show those events in more detail. For instance, how they first formed as a team, and what led to certain decisions they made. This enriches the overall understanding of the RWBY universe, even if it's not strictly part of the official story.
There's also 'Back to the Ring: A Time Travel Adventure'. This story follows a group of adventurers who accidentally travel back in time to Middle - earth. They have to figure out how to get back while also getting involved in the events of the Lord of the Rings. It has a lot of action and the interactions between the time - traveling characters and the original ones are quite humorous at times.
Time travel would have a massive impact on the One Piece storyline in fanfiction. Imagine if a time - traveler went back and influenced the actions of the World Government in the past. This could lead to a completely different present. Maybe certain Devil Fruits would be in different hands, or certain islands would have different rulers. The relationships between the different pirate crews would also be affected. For example, if the Whitebeard pirates had different experiences due to time travel interference, their relationship with the Straw Hats could be altered in many ways. It would be like a domino effect, with one change in the past causing multiple changes in the present and future of the One Piece world.
Time travel for Harry could be a way to confront his past traumas. He might go back to a time when his parents were alive and get some closure. This could make him more at peace with himself and less haunted by his past. As for Tonks, time travel could expose her to different forms of magic and different social structures. If she travels to a time when pure - blood - supremacist ideas were more prevalent, she could become more of an advocate for equality. She might also see how her family has evolved over time, which could give her a stronger sense of identity and purpose.