Well, in fanfiction, the 'Naruto Sealed Hatred' form is a concept that allows for a lot of creativity. It could mean that Naruto's experiences that might have led to hatred, like the way the villagers treated him as a child, are nullified in this form. Maybe he becomes a more 'pure' version of himself. This form could also be used to set up unique storylines, such as Naruto having to face an enemy who wants to release his sealed hatred for their own evil purposes.
It can simplify the plot. Without Naruto's internal struggle with hatred, he may make more rational decisions, which can speed up the resolution of conflicts in the story.
One interesting idea could be how the sealed hatred affects Naruto's relationships. Maybe it makes his friends more cautious around him, or it could create new rivalries. For example, if the hatred seeps out in small ways, it might cause misunderstandings among his comrades in the Hidden Leaf Village.
Well, in the fanfiction, the sealed hatred could transform Naruto into a more complex character. He might start to question his own motives and actions more deeply. Since the hatred is sealed within him, he may feel like he's constantly at war with himself. This internal conflict could lead to him making different decisions than he would in the original story. He could become more hesitant in his actions, always considering the potential influence of the sealed hatred on his choices, which is a big departure from his more straightforward and impulsive nature in the main Naruto storyline.
Naruto might also face hatred by becoming stronger. He trains harder and shows his opponents that he is not someone to be underestimated. For instance, if a group of rogue ninjas hates him because they think he's too idealistic, he proves them wrong by defeating them in combat and showing that his ideals are what make him strong.
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.
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.
Well, in some Naruto fanfictions, Bardock might be sealed by powerful jutsu. Maybe a dark ninja uses a forbidden sealing technique to lock him away, preventing him from interfering with their evil plans.
Well, one reason could be that the author wants to explore an alternate universe. Maybe in this fanfiction's version of the Naruto world, the events leading to the sealing of the Kyuubi never occurred. It could be due to different political situations among the ninja villages, or perhaps a different chain of events that prevented the Kyuubi's attack on Konoha in the first place. So, without the attack, there was no need for the seal.