Maybe a story where a future scientist discovers a way to communicate with a brilliant mind from the past, like Einstein. They work together across time to solve a great mystery that affects both their eras, such as a threat to the fabric of time itself.
One idea could be a time - traveling hero from the past who gets stuck in a high - tech future world and has to adapt to new technologies while using his old - fashioned skills to solve problems. For example, a medieval knight in a world of flying cars and laser guns.
One idea could be that an old enemy from the past resurfaces in the future, but with new and more powerful abilities. The dragons and riders have to combine their old - school knowledge with the new technology they've developed over time to defeat it.
One plot idea could be Merlin traveling to the future and finding that magic has been completely forgotten. He then has to figure out a way to re - introduce magic without causing chaos. Another could be a future descendant of Merlin's friends coming back to the past and accidentally changing the course of history, so Merlin has to fix it. A third idea is that in the future, there is a new dark magic threat that can only be defeated with the knowledge Merlin has from the past.
Perhaps past versions of the Crystal Gems meet their future selves. They could be shocked by how much they've changed, or they might learn valuable lessons from each other. The past Gems could see how their actions in the past led to the future they now inhabit, which could be a really interesting exploration of cause and effect.
The idea of past villains resurfacing in the future in a different form is also fascinating. Maybe Voldemort's ideology gets reincarnated in a new dark wizard, and the heroes from the past and present have to team up to defeat this new threat. This would show how the past and future are intertwined in the fight against evil in the wizarding world.
One idea could be that Riley and Maya are now teachers at their old school. They have to deal with a new generation of students who are facing different but equally challenging problems. It would be interesting to see how they use their own experiences growing up to guide these kids.
A plot where the past and future ninja teams have to compete in a tournament. Each team has their own set of skills and strategies based on their time periods. The past teams might rely more on brute force and basic jutsu, while the future teams have more advanced and unique jutsu. It would be a great opportunity to see the evolution of ninja techniques and how the different generations interact.
A cool plot twist could be that future Obito is actually there to stop past Kakashi from making a certain decision that would have far - reaching negative consequences. Another one might be that past Kakashi discovers that future Obito has a hidden agenda that is not what it seems at first.
Another theme is the exchange of knowledge. For instance, a character from the past might have some unique skills or knowledge that is valuable in the future, and vice versa. They then share and learn from each other, like an ancient herbalist teaching future doctors about natural remedies that have been forgotten.
One idea could be exploring how Naruto's children deal with new threats to the Hidden Leaf Village. Maybe they face a villain who has found a way to use ancient, forbidden jutsu that Naruto and his friends had long forgotten about.
One idea could be Naruto's son or daughter discovers a new and powerful jutsu that was lost in time. This jutsu could potentially change the balance of power in the ninja world.