Another plot might be that they accidentally travel back in time and end up changing some small events which have big consequences in the future. So they then have to find a way to fix those changes while also dealing with the past's different challenges. They could befriend a younger version of an important character and have to protect that person from threats that didn't exist in their original timeline.
A possible plot could also be that they travel to the future instead of the past. In this future, they see a desolate world where Fairy Tail has been destroyed. They then have to figure out what led to this and try to change the course of events in their present time to avoid this dark future.
One interesting plot could be Team Natsu traveling back in time to prevent a great disaster that they know will happen in the future. For example, they might go back to stop the resurrection of a powerful dark wizard that later causes chaos in their own time.
One interesting plot could be that Team Natsu travels back in time to the founding of their guild. They get to meet the original members and learn about the guild's true origins. This could lead to some really cool interactions and revelations about the guild's history.
One interesting plot could be that Natsu and Wendy travel back in time to the era when dragons were still abundant. They could learn powerful dragon - slaying magic directly from the dragons, which would not only enhance their powers but also give them a deeper understanding of their own abilities and the history of dragon slayers. This could lead to new friendships with the dragons and change the course of future events in their original timeline.
Obviously, Natsu Dragneel is one of the main characters. His impulsive nature often leads to interesting situations during time travel. Lucy Heartfilia is also important as she might use her celestial magic in unexpected ways in the different time periods. Gray Fullbuster, with his ice - magic, could be involved in battles against past or future enemies. And Erza Scarlet, with her strong combat skills and leadership, would play a crucial role in guiding the team through the challenges of time travel.
Well, one interesting concept could be alternative historical discoveries. For example, in some fan fictions, the Time Team might find evidence of a lost civilization that was previously unknown to historians. Another concept could be different team dynamics, like a new member joining the team with a unique skill set that changes the way they approach excavations.
A really cool plot might be that Kakashi time travels and discovers a hidden conspiracy in the past that was related to Team Minato. He then has to work with his past comrades, including Minato, to uncover the truth and prevent a great disaster that he knew about from his own time.
Well, a plot might involve Team RWBY traveling back to the time when the first Huntsmen and Huntresses were being trained. They could get involved in the early development of combat techniques and weaponry. Maybe they end up influencing the way things are taught, for instance, introducing some of their more modern strategies. Or perhaps they go back to a time when a powerful relic was first discovered and have to protect it from falling into the wrong hands, which could change the entire future of Remnant.
One interesting plot could be Natsu going back in time to prevent a great disaster that happened in the past of his world. For example, he might try to stop the initial attack of a powerful dark guild that had long - lasting negative impacts. Another plot could involve Natsu traveling back to his own childhood and having to deal with his past self, which could lead to some comical and heartwarming moments as he tries to impart some of his current wisdom.
One possible interesting plot could be about changing a historical event and dealing with the unforeseen consequences. For example, a character might go back in time to prevent a war, but then realizes that this action led to other negative outcomes like economic collapse.
Another plot might involve Marie Antoinette herself time - traveling to the future. She would be shocked by the modern world, with its different social structures and technologies. She could then use her knowledge of the past to offer unique perspectives on modern issues like inequality, as she had witnessed extreme class differences in her own time.
One good plot could be Kakashi going back in time and using his future knowledge to prevent the death of his comrades in Team Minato. For example, he might be able to stop Obito from getting crushed in that rockslide. Another plot could involve him trying to change the course of the war by influencing key decisions made by his team. He could also go back and try to train himself better in the past, using the skills he's learned in the future.