A 'naruto vs jigen fanfic' could be really interesting. Naruto is known for his never - give - up attitude. He would likely start the fight with his usual bravado and confidence. Jigen, being a more mysterious and powerful opponent, would probably initially have the upper hand. But Naruto's ability to adapt in battle is remarkable. He could analyze Jigen's fighting style during the fight and come up with new strategies. The fanfic could also introduce new elements like a power - up for Naruto or a hidden ability of Jigen that changes the course of the battle.
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 twist could be that Naruto discovers a way to nullify Jigen's power. Maybe he finds a weakness in the power source that Jigen draws from. Another twist could be that Jigen is actually being controlled by a greater evil, and Naruto has to figure out a way to free him rather than just defeat him. It could also be that Naruto loses his powers temporarily during the fight and has to rely on his wits and the help of his friends in unexpected ways.
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.
In many such fanfictions, it could be a variety of deities. It might be an ancient and powerful god from Naruto's world's mythology that the story's author has chosen to insert. For example, it could be a god of elements like a super - powerful fire god, which could give Naruto even more control over his existing fire - based jutsu and new, more extreme abilities related to fire.
In some fanfictions, Kushina was sealed into Naruto through a complex jutsu. It might be a modified version of the sealing jutsu used to seal the Nine - Tails. The process could involve special incantations and chakra manipulations.
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.
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.
In some Naruto fanfictions, Madara might be sealed through a powerful jutsu created by the main character. For example, the protagonist could combine different elemental chakra natures to form a unique sealing technique specifically designed to counter Madara's power.