One popular plot twist could be Killua going back in time and accidentally changing something that has a huge impact on his relationships. For example, he might prevent himself from meeting Gon in the first place, and then has to figure out how to get their friendship back on track. Another could be that he goes back to a time when a great evil was just starting, and he has to stop it before it gets out of hand, which completely changes the future he knew.
If Killua goes back in time, his relationship with Gon could become stronger. He might use his knowledge of their future together to avoid any misunderstandings that happened before. For example, he could be more open about his feelings and fears earlier, which would deepen their bond.
She could meet her younger self. This would be an interesting encounter as she could offer advice and guidance to her younger version. Maybe she could help her younger self to be less afraid of her powers.
I think Midoriya could be his best friend. Midoriya is kind - hearted and always looking to learn, which would appeal to Killua. They could bond over their shared desire to become stronger and protect others.
He could change the course of major events. For example, he might prevent the rise of a powerful villain. This would have a huge impact on the entire galaxy. Maybe he could save some characters who died in the original timeline.
One interesting aspect could be that Luke goes back to a time when the Sith were just emerging. He could try to root out the Sith threat before it became as powerful as it did. He might have to be very careful not to disrupt the timeline too much, but his Jedi wisdom could be a great asset in this time - traveling adventure.
In this fanfiction, Sora might change key events. Maybe he could prevent some of the tragedies that occurred in the original story. For example, he could save a character who was lost before.
One possible plot could be that Kagome goes back in time and tries to change a major event in the past. For example, she might try to prevent a big battle that had a lot of casualties. She could use her modern knowledge and skills to her advantage in the past, like using first - aid knowledge to save lives.
She might change important events in the wizarding world. For example, she could prevent certain dark magic incidents or save characters who died in the original timeline.
Well, one possibility could be that Kurama goes back to a time when he was first captured by the shinobi. He might try to change things so that he doesn't end up in their hands initially. He could use his knowledge of the future to outwit his captors and escape much earlier, and perhaps even start a new life in a different part of the world.