What are some interesting plotlines in 'Sam and Dean goes back in time fanfiction'?

In this type of fanfiction, a great plotline could be Sansa influencing the political landscape much earlier. She could use her knowledge of how certain houses would act in the future to her advantage. For example, she could form early alliances with houses that she knows will be important later. She might also try to change the way her family views certain people. Maybe she could convince her father to see Littlefinger's true nature much sooner. This would not only protect her family but also change the entire power dynamic in Westeros.

One interesting plotline could be Castiel going back in time to prevent a major disaster in the past that has far - reaching consequences for the present. For example, he might stop a powerful demon from making a deal that would later lead to the death of many hunters.

In some 'Vegeta goes back in time' fanfictions, Vegeta might go back to the time when the Saiyans were still under the rule of King Vegeta. He could try to change the Saiyan culture from being so war - like and brutal. He might introduce new ways of thinking and training that would not only make the Saiyans stronger but also more united. This could lead to a completely different future for the Saiyans, where they don't get wiped out by Frieza and instead become a more dominant force in the universe. He could also form different alliances with other races much earlier, which would change the power dynamics in the galaxy.

Perhaps he goes back in time and decides to train himself better. He could focus on mastering his emotions from the start, which might change the entire course of the Star Wars saga. He might also try to save his mother in a more effective way, without succumbing to anger and hatred.

One interesting plotline could be Inuyasha going back in time and accidentally changing something small that has huge consequences for the future. For example, he might prevent a certain event that led to him meeting Kagome in the first place, and then has to find a new way to get back to his own time while also dealing with the changes he made.

One interesting plotline could be Natsu going back in time and accidentally changing something that has a huge impact on the future of Fairy Tail. For example, he might prevent a key member from joining the guild, and then he has to figure out how to fix it.

One interesting plotline could be Naruto using his future knowledge to prevent certain tragedies. For example, he might stop the death of his parents. He could also use his knowledge of jutsu to quickly become a much stronger ninja at a younger age and change the power dynamics in the village.

A third plotline could involve Hinata going back in time and having to deal with the consequences of changing the timeline. Her actions might create new problems or enemies. For instance, if she changes a major event, it could disrupt the balance of power among the ninja villages, leading to unforeseen conflicts that she then has to resolve.

The main characters are Sam and Dean Winchester, of course. But in some fanfictions, Bobby Singer might also be involved. Since he was like a father figure to them, he could be the one guiding them through the time - travel process, or he could be there in the past waiting for them. Also, the characters of their parents, Mary and John Winchester, might show up if they go back to a time when their parents were alive.

A plotline could be that on Halloween, Sam and Dean discover a town where every year, people disappear mysteriously. They suspect it has something to do with an ancient Halloween ritual gone wrong. As they dig deeper, they find that a group of cultists are trying to summon a powerful entity. Sam uses his research skills to find a way to stop the summoning, while Dean prepares for a fight.