A possible plotline is that Naruto's transformation into a fox and time travel are linked to a prophecy. As a fox, he travels through different time periods to gather the power or knowledge needed to fulfill the prophecy. Along the way, he meets different versions of his friends and enemies, and has to learn to work with or against them depending on the situation. His fox form gives him an edge in combat and in understanding the deeper mysteries of the ninja world's past and future.
Another plotline could be that Naruto travels to the future in his fox form. In the future, Konoha is in ruins. He then has to figure out what led to this disaster using his fox - enhanced intuition and time - travel knowledge. He could then go back to his own time and take steps to prevent the events that led to the future's destruction. This would involve him facing new enemies and making tough decisions along the way.
Another plot could be that they travel to a future time where Konoha is in ruins. They have to figure out what went wrong and try to change the events that led to this destruction. Shikamaru could use his intelligence to analyze the situation, while Naruto uses his determination and strength to fight any threats they encounter. Maybe they find out that an old enemy has returned in a new form and they must stop it.
Another plot could be that Naruto is tricked into believing a false narrative about the ninja world. Similar to how Obito was manipulated by Madara's lies. He then starts to act in ways that are contrary to his usual self. He might target the other villages, thinking he is doing the right thing for some grand, but misconstrued reason. This would lead to him being at odds with his former friends, who would be desperate to bring the old Naruto back.
One possible plotline could be that Naruto is somehow transported to a world where sorcery is the main power source. He then has to learn to become a sorceress to survive and find his way back home.
One possible plotline could be that they go back in time to prevent a major disaster that happened in their own time. For example, they might try to stop the destruction of the village. Another could be that they are sent back to change the course of their own relationship. Maybe in their original timeline, they had some misunderstandings, and going back gives them a chance to fix things. It could also be that they are sent back to learn something specific, like a long - lost ninja technique that only existed in the past.
One possible plotline could be that Naruto is constantly rejected by the village he is trying to protect. This betrayal and lack of acceptance could gradually turn him dark. For example, if the villagers start to blame him for every bad thing that happens, even when it's not his fault. Another plotline might involve Naruto losing someone very close to him, like Sasuke, in a way that he blames the shinobi world for. This could lead to him deciding to take revenge on the world and turn to darker methods of achieving his goals. Maybe he starts to use forbidden jutsu without hesitation, seeing it as a means to an end.
One possible plotline could be that Naruto discovers a hidden jutsu or artifact that grants him immortality. He then has to deal with the consequences of living forever, like seeing his friends and loved ones age and die while he remains the same. Another could be that an enemy tries to steal his immortality, leading to a great battle.
Perhaps they time - travel to a time when the ninja world was at peace. Naruto, who is used to a world full of conflict, is initially out of place. Mikoto helps him adjust. They start to fall in love during their adventures in this idyllic past. They might discover secrets about the origins of certain jutsus or ninja clans that were lost in Naruto's time. Their relationship could be a source of both strength and confusion as they navigate a world that is both familiar and strange to them.
Maybe Naruto travels back in time to a point where Anko is in a difficult situation. He uses his sharinnegan abilities to help her out, and during this process, they start to develop feelings for each other that were not present in the original timeline. And as they try to return to their own time, they face various challenges that test their relationship and their new - found powers.
One possible plotline could be that Naruto accidentally travels back in time and lands right in front of Tsunade when she was at a crucial point in her life, like just after the death of her loved ones. Naruto, with his future knowledge, helps her cope and in the process, they grow closer. Another plotline could be that Tsunade is sent to the future where she meets an older and more mature Naruto. They initially clash due to their different outlooks from different times but then gradually fall in love as they understand each other better.
One possible plotline could be that Bilbo and Aragorn are sent back in time to the founding of Gondor. They use their knowledge from the future to help shape the city's early days. For example, Aragorn might introduce advanced combat strategies, and Bilbo could offer insights on building strong alliances through his hobbit diplomacy skills.