Sasuke could be in it. He might be initially skeptical of Naruto's new power but then see its potential in combat.
Obviously Naruto would be the main character as he has the power to control vacuums. His friends like Sasuke and Sakura could also be involved. Sasuke might be skeptical at first about this strange new ability of Naruto's. Sakura could be trying to find a scientific explanation for it, thinking it has something to do with Naruto's unique chakra nature.
Well, it could be about Naruto using his chakra to control paper in unique ways. Maybe he creates paper constructs for battle or uses it to send secret messages.
Well, we might see characters from other villages as well. For instance, Gaara. He could be interested in Naruto's silver control because it might offer a new way to protect his village. And there could be a mysterious antagonist who wants to steal Naruto's silver control for his own evil purposes.
It could also be a result of a powerful curse or blessing. For instance, he might be cursed by an old enemy with the ability to control time as a side - effect, but he then learns to master it. Or, it could be a blessing from a sage or some other powerful being who sees Naruto's potential and gives him this unique ability to help him save the world.
Another limitation might be the amount of chakra it consumes. Using this power too much could drain him quickly, leaving him vulnerable in the middle of a battle. Also, if there are opponents with abilities to disrupt chakra flow, they could potentially stop him from using his gravity control.
Kushina, on the other hand, might experience a loss of agency which could lead to her character growing in different ways. She could fight against Naruto's control, which would show her strong - willed nature. Or she could come to accept it and use it as an opportunity to guide Naruto in a different way. There could be a role reversal of sorts where she becomes the voice of reason in Naruto's head. And this could lead to a very different kind of relationship between them compared to what we know from the original story.
Foxes are quite common. Given Naruto's connection with the Nine - Tailed Fox, it makes sense that in fanfiction, he might be able to control other foxes. They can be used for scouting or as distractions in battles.
There could also be new characters created specifically for this fanfiction. Maybe a character who has the ability to control all forms of paper in the Naruto world and becomes either an ally or an enemy to Naruto. This new character could bring new dynamics to the story and its plot.
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.
One challenge could be that the heartless have a very different nature compared to the beings Naruto is used to dealing with. Their lack of emotions might make it difficult for him to find a way to connect and control them.