One possible new alliance in this time - travel scenario could be with the native species of different planets. Darth Vader, with his new - found desire for redemption, could use his power and influence to help these species. In return, they could offer him support. For instance, on a planet like Kashyyyk, he could help the Wookiees against the Empire's encroachment early on. This would not only be a step towards his redemption but also change the power dynamics in the galaxy at an earlier stage.
He could form an alliance with the Jedi from the past. Since he has knowledge of the future and the Sith's plans, he could convince the Jedi to take preemptive action against Palpatine. This would be a major shift as the Jedi might trust him more if he shows them the truth about the Sith's rise.
Time travel could offer Darth Vader a chance to relive key moments and make different choices. For example, he could go back to the moment before his fall to the dark side and resist Palpatine's temptations. This would completely change the course of the Star Wars saga. Maybe he would see the error of his ways earlier and not cause so much destruction.
He might be shocked by the advanced technology. The Empire's weaponry would seem primitive compared to future tech. He could also be intrigued by the new forms of the Force if they had evolved.
In a fanfiction scenario, Darth Vader time traveling to the Clone Wars could also lead to some interesting battles. He might bring with him advanced technology or fighting techniques from the future. This could make him a formidable force on the battlefield. He could face off against some of the great Jedi of that era in new and unexpected ways, changing the dynamics of combat and potentially leading to different outcomes for various battles.
One interesting plot could be Darth Vader traveling back in time to prevent his own fall to the dark side. He might try to change the events that led him to become Vader, like saving Padmé. Another could be Vader traveling to the future and seeing the downfall of the Sith, which makes him question his loyalty to the dark side. He could then try to find a way to change the future of the Sith order.
Their relationship could become more understanding. As they travel through time and see different events together, Luke would gain a deeper understanding of what led his father to become Darth Vader. Vader, in turn, might see Luke's unwavering hope and goodness more clearly, which could soften his stance.
One interesting plot could be Darth Vader traveling back in time to prevent his own fall to the dark side. He might try to change the events that led him to become a Sith, like saving Padmé.
Enemies could be many. In the past, he might face Sith Lords who don't want him to change the timeline and disrupt their plans. In the future, he could encounter new galactic powers or beings with strange powers that oppose his presence. For example, a future race that has developed technology to counter the Force.
If Darth Vader travels to a time when he was still Anakin Skywalker, he might have a chance to redeem himself earlier. Seeing his younger self could make him realize the mistakes he made and try to change the path that led to his dark transformation. His character could become more complex as he battles with his past self's idealism and his current self's dark nature.
Perhaps they time travel to a parallel universe. In this universe, Darth Vader never turned to the dark side and Anakin Skywalker remained a Jedi. Luke would be able to see how different things could have been. This experience might inspire Vader in their own universe to try and find a way back to the light side, and they could then work together to bring positive change to their own timeline.
In a time - travel scenario, Naruto's exuberant personality could initially shock Tsunade. But as they spend more time together, Naruto's determination to protect might make Tsunade see him in a new light. His growth and understanding of the past could also intrigue her. Maybe they'd start off as comrades trying to fix things in the past, and slowly feelings would develop as they rely on each other more and more.