The marauders' presence in 1995 would likely disrupt the normal flow of things. They could influence the relationships between the characters. For example, they might become friends with the Weasley family and introduce some new pranks or ideas to them. Their knowledge of the past could also help in dealing with Voldemort, but it could also create confusion as they may not fully understand the current situation. And they may have some conflicts with certain characters who don't trust their sudden appearance.
His presence could disrupt the power balance. If he still has his strong Force abilities, he could be a major force (no pun intended) to be reckoned with. Those in power might see him as a threat or an opportunity. If he aligns with one side, it could tip the scales in their favor.
The Marauders' presence would likely change the dynamic completely. They could offer advice to Harry based on their own experiences. For instance, James could share how he won over Lily, which might influence Harry's approach to Ginny. Also, their very existence in the fanfiction world could introduce new plotlines. Maybe they could help Harry and Ginny solve some problems that they couldn't have solved on their own. And their different personalities would also have an impact. Sirius' boldness and Remus' wisdom would both play a part in shaping the story.
If Kakashi travels back in time, his actions could have a butterfly effect. For example, if he saves someone who was supposed to die, that person's actions in the future could be completely different. This could lead to changes in alliances, battles, and even the political structure of the village.
Naruto's knowledge from the future could have a huge impact. He might introduce new fighting techniques or ways of thinking that were not present in the past. This could change the balance of power among the ninja villages. Also, his actions could influence the relationships between different clans. For example, if he befriends a clan that was previously isolated, it could lead to new alliances and change the political landscape of the ninja world.
Harry's time travel might change the Marauders' fates completely. They could form a stronger alliance against Voldemort with Harry's help. Maybe they would be able to discover more about Voldemort's secrets earlier. And their relationships would also be different. Sirius and Remus would not have to suffer the loss of their friends in the same way.
For Boruto, time traveling might make him more appreciative of the past and how hard his father worked to build the world he lives in. He could become more humble and learn from the simplicity and determination of the past generations. His friends, too, might gain a new perspective on their own lives. For example, Sarada could see how her mother was as a young kunoichi and understand her better.
Naruto's presence in the past could have far - reaching consequences for the future. His actions to save Kushina could potentially prevent certain events that led to the rise of villains in the original timeline. For example, if the Nine - Tailed Fox attack is thwarted successfully, it might change the circumstances that led to the creation of certain anti - village groups. Also, Naruto could influence the development of new ninja arts in the past, which could then be passed down through the generations and make the village even more powerful in the future.
You can have existing characters like Handsome Jack be affected by time travel. For example, he could be sent back to a time when he was just starting his rise to power. This would show a different side of him, perhaps more vulnerable or idealistic before he became the tyrant we know. The Vault Hunters could then interact with this younger Jack and either try to change his future or be influenced by his earlier ideas.
James might become more cautious. The future could be full of things he doesn't understand, so he might not be as brash as he was in his own time.
Their relationships could become stronger as they face the new and strange future together. They would rely on each other more in this unfamiliar setting.