They might change some crucial events in their past. For example, Stefan could prevent some of the bad things he did while being a ripper. Caroline, on the other hand, could go back to when she was a human and make different choices about her relationships or her path in life.
In this fanfiction, they could meet their past selves. This would be really interesting as they would have to deal with the shock of seeing their younger versions. Stefan might try to give his past self some advice on how to control his bloodlust better. Caroline could encourage her past self to be more confident. And maybe they would end up changing the whole course of their future in ways they didn't expect.
It could start to develop in new ways. For instance, if they go back to a time when Stefan was still with Elena, Caroline might see a different side of him. This could either make her fall for him more or create some tension between them. But as they work through these issues, they could end up with a deeper and more complex relationship. They might also discover new things about each other that they didn't know before, like hidden fears or desires from their pasts, which would bring them closer together.
Perhaps in the fanfiction, they go on a honeymoon to a place that has significance to both of them in their past. It could be a place where they first met as vampires or a place that was important in their human lives. Along the way, they encounter other supernatural beings that test their relationship. But their bond as a married couple is strong enough to overcome these obstacles.
Well, one possibility is that they could completely rewrite the history of the ninja clans. Naruto, with his positive influence, might be able to make the Uchiha clan feel more accepted in the Leaf Village, preventing the Uchiha massacre. Obito, having seen the destruction his actions caused in the future, could help Naruto in these efforts. Also, they could work together to train younger versions of themselves and their friends to be even stronger, which would have a huge impact on future battles.
Well, they might change some major events. For example, they could prevent a big battle that had a lot of casualties in the original timeline. Maybe they'd help their parents at a younger age, giving them an edge in fights. They could also introduce new techniques to the past, which would change the power balance among the Z - fighters.
Maybe they would meet their ancestors. Percy could see his Greek hero predecessors and Artemis might interact with the first hunters she ever had. This could lead to some interesting exchanges, like learning forgotten hunting techniques or ancient combat skills.
In a time - travel fanfiction like this, they could also have the opportunity to meet long - lost characters or discover secrets that were lost in time. Naruto and Shikamaru could learn about the origin of some of the powerful jutsus in their world. And perhaps they could use their knowledge of future technology or ninja tools to create something revolutionary in the past. This could potentially change the balance of power among the ninja villages. However, they would also have to be careful not to be discovered as time - travelers, as that could lead to all sorts of complications.
Well, they might prevent some great tragedies in the Star Wars universe. For example, they could stop Anakin from turning to the Dark Side. This would completely change the course of history in the galaxy.
Well, they could also change their own relationships. Maybe Naruto wouldn't be so alone as a child, and Ino could become a stronger ninja earlier. They might train together in ways they didn't before, using the knowledge of future jutsu and strategies. They could also influence the relationships between different ninja clans, like improving the relations between the Uzumaki and the Yamanaka clans.
Well, they might change some important events. For example, they could prevent certain tragedies from happening in the wizarding world. Maybe they'd save some characters who died in the original timeline.
Another plotline could be that they accidentally travel to the future and have to deal with the consequences of seeing their future selves. They may discover things about their relationship or the vampire world that they didn't expect. Sometimes, they are on a mission in the future to prevent a disaster from happening in their present time. This involves a lot of action and adventure as they try to figure out how to stop the impending doom while also dealing with the strange future world they find themselves in.