One possible plotline could be Grogu traveling back to the time of the Jedi Order's prime. He could meet the great Jedi Masters and learn from them directly. This would be amazing as he could gain more knowledge and skills, and it might also change the course of his own future.
Grogu could also time travel to a time during a great battle in the Star Wars universe. He might find himself in the middle of the Clone Wars or the Galactic Civil War. There, he could play a crucial role in turning the tide of the battle, either by using his unique Force abilities or by inspiring others to fight for what's right. This would add a lot of action and adventure to the fanfiction.
Well, in a Naruto time travel future fanfiction, a plotline could be Naruto finding himself in a future where the chakra system has been completely disrupted. People are suffering because of this. He uses his time - traveling knowledge to find a way to fix it. Another idea is that he travels to a future where the five great nations are at war again, but this time it's a more technological and brutal war. He has to use his experience and charisma to stop the war and bring peace once more.
One possible plotline could be Megatron traveling back in time to prevent his own creation. This would create a paradox as his actions in the present are a result of his past self. Another could be him going to a time when the Autobots were at their weakest and trying to finish them off once and for all.
One possible plotline could be traveling back to the time of Julius Caesar. The protagonist could get involved in the political intrigue, perhaps even influencing the events leading to Caesar's assassination. Another could be going to the height of the Roman Empire and experiencing the grandeur of the Colosseum, interacting with gladiators and senators.
If Grogu travels back in time, he might become more confident in his abilities. Meeting powerful Jedi in the past could give him role models and a better understanding of his own potential. For example, if he meets Yoda as a youngling, he could learn how to better control his Force powers and be more assertive.
One possible plot twist could be that Narukaka travels back in time and accidentally changes a small event that has huge, unforeseen consequences in the future. For example, preventing a minor meeting between two people that was supposed to lead to a great discovery.
One possible plot twist could be Sandor traveling back to his childhood and preventing the incident that scarred him. This would completely change his character arc and his relationship with his brother. He might become a more confident and less bitter person.
One possible plot twist could be that Naruto and Jiraiya travel back to a time when the Uchiha clan was at its peak. This would put Naruto in a position to potentially prevent the Uchiha massacre. He could use his knowledge of future events and his skills to change the course of history for the better. Jiraiya, on the other hand, could discover secrets about the Uchiha that were lost over time.
One possible plot twist could be that Luffy and Robin travel back in time to the Void Century. This would open up a whole new world of exploration as they discover the true history of the world. They might encounter the Ancient Kingdom and learn the secrets that have been lost for so long. It could also put them in a dangerous position as they might be hunted by the World Government who wants to keep that history buried.
One possible plot twist could be Naruto changing the past in a way that completely alters the future relationships. For example, if he prevents a certain event that led to a character's death, it could change the whole dynamic among the characters. Another twist could be that Naruto discovers that the past is not as simple as he thought, and there are hidden forces at work that he didn't know about in his original timeline.
Another exciting plot could involve Peter Quill traveling to different points in time to collect powerful artifacts. Maybe he discovers that these artifacts, when combined in a certain way, can give him the power to defeat a great evil in his own time. Along the way, he meets different versions of his friends and enemies from various timelines.