Her friends from her own time could potentially be her allies even when she goes back in time. For example, if she has a special bond with Weiss, Weiss might be able to sense Ruby's presence in the past in some way and offer help. Another possible ally could be a character from the past who she befriends, like an old wizard who recognizes Ruby's special powers and decides to help her on her mission.
There's a possibility that a new character could emerge as the main antagonist. Ruby's time - traveling could disrupt the normal flow of events, and this might create a new power - hungry or revenge - seeking character. This new antagonist could be someone who blames Ruby for the changes in the timeline and wants to stop her at all costs.
Well, one possible plot development could be Ruby using her knowledge of future events to prevent certain tragedies. For example, she might stop the fall of Beacon earlier than it originally happened. Another could be her trying to change the relationships between the characters for the better. Maybe she'd make sure Weiss and Blake become friends more quickly. Also, she could work on improving her own skills faster by learning from her past mistakes.
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.
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.