She'd be in a state of shock. Kushina is a strong - willed character, but the news of Naruto's death would be too much to bear. She may isolate herself from others as she tries to come to terms with the loss. Her chakra, which has always been a part of her identity, might even seem to dim as she is overcome with sadness.
She would likely be devastated. Kushina has a deep connection to Naruto as his mother. She might first go into denial, unable to accept that her son is gone. Then, she would probably be filled with intense grief and anger. She could potentially lash out at those she blames for his death or just break down completely, mourning all the things Naruto could have been and all the time they missed when he was growing up.
She might be overjoyed. After all, Naruto is her son. She could immediately rush to find him and embrace him tightly, tears of happiness streaming down her face.
Well, Kushina could initially be disappointed. But then she might see it as an opportunity to help Naruto find his true passion. She could start introducing him to different things, like maybe some traditional Uzumaki family skills that don't necessarily involve being a ninja in the typical sense. This way, Naruto could still have a sense of purpose and connection to his heritage.
Naruto's reaction could be complex. On one hand, he would be happy to find someone else from his clan. He has always been proud of his Uzumaki heritage despite not knowing much about it at first. But on the other hand, he might be a bit cautious. Karin has been associated with some not - so - good groups in the past. However, overall, his positive nature would probably lead him to approach Karin with an open mind and try to build a connection with her based on their shared Uzumaki roots.
She might be horrified and immediately take steps to protect Sirius. For example, she could confront the abuser or report it to the proper authorities within the wizarding world.
Well, Bellatrix is a very unpredictable character. In this fanfiction scenario, she could react with glee. Since she's on the side of the Dark Lord, she might think that Harry's abuse has made him more vulnerable. She could also be curious about who would dare to abuse 'the Boy Who Lived'. However, she might also be angry that someone else has been causing harm to Harry when she believes that's her Dark Lord's prerogative.
Sasuke might be initially shocked. He has always seen Naruto as a rival and suddenly finding out Naruto is a girl could completely change his perception. He may start to view Naruto in a more protective way, as his traditional views of gender roles might make him feel the need to safeguard her now that he knows she's female.
Well, Kakashi is a complex character. When he discovers Naruto is abused in the fanfiction, he may first feel a deep sense of guilt for not noticing earlier. He'd then use his skills and influence in the village. He could start by reporting it to the proper authorities in Konoha, like the Hokage. And at the same time, he'd be there for Naruto, providing emotional support, talking to him, and helping him through the trauma. Kakashi has his own past traumas, so he'd understand what Naruto is going through on some level.
She might be shocked and feel a great deal of sympathy for Percy. She could immediately try to comfort him and assure him that he's safe now.
She might be shocked at first. After all, it's not every day you find out your friend is a superhero. But then she could also be really excited and proud of him.
Naruto might initially be confused. He has grown up with a certain view of himself, and this new information about his heritage completely shatters that. He may struggle with his identity for a while, but as he digests the information, he could start to feel a sense of pride. He might think that now he has a greater purpose, something that ties him more closely to his family and the ninja world in general. He may also become more confident in his abilities, knowing that he comes from a great lineage.