Kushina returning to find crazy Naruto fanfiction could lead to a whole range of reactions. Firstly, she might be appalled at how some fans have twisted the story of her son. On the other hand, she could be amused by the wild ideas. If she finds fanfictions that involve her own backstory in strange ways, she might feel a bit violated but also intrigued. For instance, if there's a fanfiction where her relationship with Minato is completely different from what it really was, she'll have a strong reaction. But overall, it would be a very interesting encounter between her and the world of Naruto fanfiction.
She could be angry if the fanfiction distorts Naruto's character or the story in a negative way. For example, if Naruto is portrayed as a bad person in the fanfiction, Kushina, as his mother, would not like it at all. But if she finds some positive and creative fanfictions, she might be impressed by the fans' imagination.
In this fanfiction, the plot might involve Kushina coming back to help Naruto in his toughest battles. Maybe she uses her unique chakra abilities that Naruto has inherited to give him an edge. She could also provide emotional support, as Naruto has always longed for his mother.
Obviously, Kushina is one of the main characters. Naruto is also a central figure as her son. Since it's related to the Naruto universe, characters like Sasuke, Sakura, Kakashi might also be important in the fanfiction. They could interact with Kushina in various ways, like Sasuke might be skeptical of her at first, or Sakura could be eager to learn from her.
Minato is often paired with Kushina in these fanfictions. Their relationship was a significant part of the Naruto story, so many fanfictions expand on their love story. Another popular pairing is Kushina and Naruto. It could be a story where Kushina is brought back to life and gets to be a part of Naruto's life in a more direct way.
She could also be amused in some cases. If the fanfiction has some really out - there but harmless ideas about Naruto, like him having a strange hobby that doesn't really change his fundamental good nature, Kushina might find it funny and just shake her head at the creativity of the fanfiction writer.
There could be a scenario where Kushina comes back to life somehow in the fanfiction. She might then play matchmaker between Naruto and Hinata, using her knowledge of Naruto to help Hinata understand him better. For example, she could share stories of Naruto's childhood that would make Hinata feel closer to him.
One possibility in such a fanfiction scenario is that Kushina's own chakra, which was already special as an Uzumaki, could have an impact on Naruto while he's sealed within her. It could either strengthen him in some ways or cause unforeseen consequences. Also, characters like Minato would have a different relationship with the situation. Instead of seeing Naruto as his son on the outside, he might be more focused on the presence of Naruto within Kushina, which could change how he approaches protecting his family and the village.
In this fanfiction, Naruto might finally get the motherly love he always craved. Kushina could share her unfulfilled dreams for Naruto, like seeing him grow up without the pain of being an orphan. They would probably have an emotional conversation about Naruto's father too.
In this fanfiction, their marriage could also lead to new ninja techniques being developed. Kushina was a powerful kunoichi, and Naruto has his own unique abilities. Combining their skills and knowledge, they could create something entirely new. This could have a significant impact on the Hidden Leaf Village, making it even stronger in the face of threats.
In fanfiction, this could be due to an alternate reality or a dark twist in the plot. Maybe Kushina was mind - controlled by some powerful enemy. It's a very strange and dark concept that goes against the normal Naruto storyline where Kushina is Naruto's mother and loves him dearly.