His Force abilities could be different. Maybe he would discover new aspects of the Force in the past that were lost in his original time. For example, he could learn ancient Force techniques that were forgotten over time.
His ability to manipulate his surroundings could change. If he goes back to a time when technology was different, he would have to adapt his abilities. He might find new ways to use the Force to interact with the less advanced technology of the past, or he could use his knowledge of future technology to create something unique in the past.
His combat abilities might be overpowered in some earlier time periods where the fighting styles are less developed. For example, if he travels back to a time when lightsaber combat was more rudimentary, his advanced techniques could make him seem like a god of war.
Well, if Draco goes back in time, he might become more humble. Seeing the past and the mistakes his family has made or is about to make could make him less arrogant. He would realize that his pure - blood status doesn't give him the right to look down on others.
In the era of the Old Republic, Starkiller's abilities would be quite different. The Force was more in tune with the natural order then. His raw power might be more subdued as he would have to adapt to the more traditional ways of the Jedi and Sith. For example, his lightsaber combat might become more refined in the style of the ancient Jedi, rather than his more aggressive style from his own time.
His confidence might increase. Since he already knows what's going to happen, he would be more self - assured in his actions. For example, he wouldn't be as intimidated by Snape.
His relationship with Kakashi would also change. Naruto could use his Rinnegan - enhanced knowledge to help Kakashi deal with his past traumas earlier. He might also show Kakashi new jutsu or ways of combat that he learned in the future. This would make Kakashi see Naruto in a whole new light and their bond could become more of a teacher - student relationship in reverse.
With his Slytherin peers, Draco's relationship would shift. He might encourage them to be more inclusive and less focused on pure - blood supremacy. This could make him an outcast among some of the more traditional Slytherins, but also gain him new allies who are open to change.
His relationship with his father, Ned Stark, would be different. He could finally have a real father - son relationship instead of the hidden one. He might be able to learn from Ned and become an even better leader in the North.
His relationship with Katara would be very different. He might be able to approach her in a more confident way, knowing what they've been through in the future. He could also avoid some of the misunderstandings that happened between them in the original timeline.
Regarding his relationships with his friends and comrades, like Samwell Tarly, things would be altered. He might not meet Sam in the same way as before. And his relationship with Daenerys Targaryen could be completely different. Instead of meeting her during the events of the original story, he could meet her when she was much younger, and this could lead to a very different kind of relationship, maybe one that's more of a mentorship or a completely different romantic connection.
If Thor goes back in time, his relationship with Loki would be very different. In the past, Loki might not be as bitter and jealous as he becomes in the future. Thor could try to be a better brother and prevent Loki from feeling left out, which would change their entire dynamic. With his friends like the Warriors Three, he might be more protective of them in the past, knowing the challenges they will face in the future.