In some fanfictions, it might be due to an alternate timeline or reality. A change in the past could lead to Kushina having different beliefs or loyalties. It could also be related to a new power or curse that affects her judgment and causes her to see Naruto as an enemy. However, this is often a very dark and dramatic turn in fanfiction stories.
Perhaps there's a time - travel element involved. Naruto from the future, who has been through some horrible experiences, travels back in time and, in a state of confusion or rage, attacks Kushina. Or it could be that a powerful villain has the ability to manipulate Naruto's emotions and uses that power to make him turn on his mother. This would create a very complex and dark plotline that challenges the normal Naruto narrative.
In fanfiction, the idea of Naruto attacking Kushina is very uncharacteristic as they are mother - son. It could be a very dark or alternate universe scenario. Maybe in a plot where Naruto is mind - controlled or in a completely warped reality where family bonds are reversed.
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.
Naruto would likely be deeply hurt, not just physically but also emotionally. He has always idolized his mother, so an attack from her would be a huge blow to his psyche. His trust in family and those close to him could be severely damaged.
One possible reason could be mind control. Maybe an enemy of the village found a way to manipulate Kushina's mind and make her turn against her own baby. Another reason might be a misunderstanding. For example, she could have been tricked into believing that Naruto was a threat to the village in some way.
Well, in a fanfiction, it might be due to a curse. There could be a curse placed on Naruto that slowly transforms him into Kushina Uzumaki. This curse could be related to some dark secret in the Uzumaki clan's past. Or perhaps a strange experiment by Orochimaru or another rogue ninja that goes wrong and causes Naruto to take on Kushina's form and some of her abilities.
One way it could happen is if Naruto somehow gains the ability to travel back in time. Maybe through a powerful jutsu or a unique kekkei genkai. He could then use his knowledge of future events and his combat skills to save his parents from their tragic fate.
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.
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.
Well, Naruto could save Kushina from the Kyuubi in fanfiction through his strong willpower. We know Naruto has an unbreakable spirit. He might be able to communicate with the Kyuubi in a different way, like showing the Kyuubi a future where it doesn't have to be so violent. And by doing this, he could convince the Kyuubi to release Kushina. Also, Naruto might have received some special power or training that enables him to counter the Kyuubi's attack and save Kushina.