naruto gets sealed away

It could be Orochimaru. He has always been interested in power and Naruto's unique abilities. With Naruto sealed away, Orochimaru might see it as a chance to steal whatever power Naruto had or use his absence to further his own evil plans in the ninja world.

One possible plot development could be that the village is thrown into chaos without Naruto. His friends might initially feel lost but then come together to find a way to bring him back. For example, Sasuke could put aside his differences and join forces with the others, realizing Naruto's importance to the village and to him personally.

In such a fanfiction, the Fairy Tail guild might be thrown into chaos. They could initially be confused about this strange event from another world. Some members might see Naruto's sealing as a threat to their world's balance, while others might be more curious and try to find a way to break the seal.

One possible reason could be that his godlike powers were seen as a threat. The village elders or some powerful forces might have feared that Naruto, with his immense strength, could lose control and cause destruction. So, they decided to seal him away to protect the village and the world at large.

Perhaps Percy discovers a secret that is so dangerous that the powers - that - be decide to seal him away to keep it safe. It could involve a prophecy that he might fulfill in a way that would change the world in a way they don't want. So, they use some ancient magic or a powerful artifact to seal him. For example, if there's a prophecy about Percy uniting two warring factions in a way that would upset the current balance of power, those in power might try to stop it by sealing him away.

Maybe it's an ancient and powerful entity that has been awakened. Percy might be in the wrong place at the wrong time and this entity, seeing Percy as an intruder or a potential disruptor of its slumber, decides to seal him away using its otherworldly powers.

I'm not entirely sure as I haven't read that specific fanfic. But it might be about Naruto being sealed away in some way, perhaps in a different scenario from the original story. Maybe some new villain or power manages to seal him.

The story could also focus on the efforts to unseal Naruto. His friends and the characters from the crossover world could embark on a dangerous journey to find the key or the magic to break the seal. In a Naruto - Harry Potter crossover, Hermione might use her vast knowledge of magic to research a way to free Naruto from the seal.

One possibility is that the story could focus on how the village copes without Naruto. Maybe there would be a different kind of unrest or a search for a new way to deal with the Nine - Tails' power. Without Naruto, characters like Iruka might have a different role, perhaps becoming more involved in trying to find a solution to the power void.

Well, perhaps in this fanfiction, the Avatar enters the Naruto universe and causes some sort of imbalance. Naruto, seeing the chaos it might bring, decides to seal away the Avatar. As time passes, Naruto starts to learn more about the Avatar's world and realizes that there are good things about the Avatar too. So he begins a journey to find a way to unseal the Avatar without causing more harm, all while facing enemies who want to use the situation for their own gain.