Some fanfictions focus on Bran traveling through time during the events of the War of the Five Kings. He could go back and forth in time to gather intelligence for Robb Stark, his brother. This would give Robb an edge in his battles, as he would be aware of the enemy's moves before they happen. Or, Bran might time travel to try and prevent the Red Wedding, which was a major turning point in the war and led to the downfall of House Stark at that time.
One popular storyline could be Bran going back in time to prevent the death of his father, Ned Stark. This would completely change the course of the story as Ned played a crucial role in the political drama of Westeros. Another could be Bran traveling back to the time of the First Men and learning ancient magic that he then uses to fight the White Walkers in his own time.
When Bran time travels, he might interact with characters in the past. Let's say he goes back to when his mother, Catelyn, was a young girl. His presence could influence her decisions, and this in turn would affect how she treats the Stark children in the future. For the other lords and knights, if Bran changes historical events, their loyalties and actions could be completely different. Maybe some who were once enemies become allies, or vice versa.
One popular Bran Stark fan fiction might be those that explore his journey in mastering his warging abilities further. For example, there could be stories where he uses his powers to communicate with ancient spirits of the North, uncovering long - lost secrets about his family's past and the history of Westeros.
In some fanfictions, Sansa travels back to a time when she first meets Joffrey. She then uses her new - found time - traveling wisdom to avoid getting engaged to him. She could instead manipulate the situation to get betrothed to someone more favorable to her family. This would completely change the course of events, not only for herself but also for the whole Stark family and the Seven Kingdoms.
In some fanfictions, Morgan Stark travels back in time to experience different timelines. For example, she could go to a timeline where the Avengers never split up. There, she gets to see how a united team functions and learns new skills from the heroes. She might also travel to a time when her father was still alive but in a difficult situation, like during the events of Civil War, and tries to bring peace between the two factions by using her unique perspective as someone from the future.
One interesting storyline could involve the Straw Hats traveling through time and meeting their younger selves. This would create some really cool character - development moments. For instance, Luffy could meet his younger self and give him some advice on how to become a great pirate. Or, they could time - travel to a period when a powerful devil fruit was first discovered. This would lead them on a quest to either obtain it or prevent it from falling into the wrong hands. Additionally, they might time - travel to an era where different races had more significant roles in the world, and they'd have to deal with the cultural differences and power dynamics of that time.
One popular storyline could be about a Spartan going back in time to prevent a major disaster in the Halo Wars timeline. For example, they might stop a key Covenant leader from being born, thus changing the course of the war. Another could involve time-traveling to retrieve lost technology from the past to use against the enemy in the present. And some might focus on the ethical dilemmas of time travel, like whether changing the past is really the right thing to do even if it could save lives in the future.
Another factor is the mystery surrounding Lyanna. Time travel allows the authors to play with the mystery, to reveal new secrets or create new ones. It also adds an element of adventure and unpredictability. Readers are drawn to the idea of Lyanna traveling through time, interacting with different versions of characters, and perhaps changing the very fabric of the story they know so well.
In certain fanfictions, the use of Rinnegan - powered time travel could lead to the discovery of hidden secrets in the Naruto world. As for the harem, the main character might find himself in situations where he has to protect multiple female characters during his time - traveling adventures. This protection and shared experiences could then lead to the formation of the harem. For instance, he travels to a time when the Akatsuki is more active and saves some female ninjas from their attacks, and they fall for him.
Another storyline could involve Natasha exploring her past in more depth during the time travel. She could interact with her younger self, giving advice or just sharing experiences. This could lead to a whole new level of character development for her. For instance, she might help her younger self become a better spy earlier on, which would then have a butterfly effect on the future events in the MCU timeline.
Well, often in fanfiction, Jon Stark is involved in romances. He might have a relationship with a character who was just a minor figure in the original Game of Thrones. For example, he could fall in love with a Northern girl from a small village who has some special powers. This kind of relationship gives a new dimension to his character as he tries to balance his love and his duties towards his family and the North.