The Karma Seal can change Naruto's appearance. In some fanfictions, it might give him a more menacing look with strange markings spreading across his body.
Naruto might be a great professor for a class on the study of magical creatures. His curiosity and ability to befriend all kinds of beings in his own world could translate well. He could teach students how to approach magical creatures with respect and understanding, just as he did with the giant toads and other beasts in his ninja journey.
It could lead to some really interesting plot twists. Naruto's new ability as a seal master might give him an edge in battles and change the dynamics of his relationships with other characters.
One possible consequence could be a change in Naruto's power level. If Hinata can control the seal, she might be able to regulate the flow of power from it, which could either enhance or limit Naruto's abilities.
Perhaps an unknown hermit living in some far - off place. In many fanfics, there are mysterious characters that pop up with unique knowledge. This hermit could have mastered the Reaper Death Seal long ago and sees Naruto's potential, so decides to teach him.
One consequence could be that it changes the power dynamics among the Hyuga clan. Since the Caged Bird Seal was used to control the branch family, its removal might lead to a more equal power distribution within the clan.
Neji might gain a significant boost in power. Without the seal suppressing him, his chakra flow could become more natural and stronger. He could potentially unlock new abilities or improve his existing ones, like his Gentle Fist technique becoming even more potent.
In many fanfictions, Naruto might use his unique chakra, perhaps enhanced by his Uzumaki heritage or the Nine - Tails' power. His strong will and connection to his friends could also play a role, allowing him to find a way to break the seal through sheer determination and his belief in Neji's potential.
The curse seal often gives characters increased power. For example, they might become stronger physically, able to take on tougher opponents. In some fanfiction, it can also change their appearance, like making their eyes glow or their skin take on a different hue.
There could be a situation where an ancient technique is awakened within Hinata. This technique might have been long forgotten, but due to certain events in the fanfiction world, it resurfaces. This ancient technique could be the key to her being able to control Naruto's seal. It might involve her chakra nature or some spiritual connection she has with the seal's origin or the entity that placed the seal on Naruto in the first place.