One interesting aspect could be the exploration of a darker side of Naruto's character. Maybe in the fanfiction, Naruto has faced some extreme hardships that led him to this darker path. For Kushina, it might involve her relationship with a dark Naruto in a way that is different from the original story. For example, she could be trying to save him from the darkness.
Some stories in this fanfiction might focus on the consequences of Naruto being dark on the entire ninja world. Kushina could be brought back in some way, perhaps through a jutsu or a special plot device. She then has to deal with a Naruto who is not the same as the son she knew. This could lead to a complex exploration of family, love, and the struggle between good and evil.
Perhaps they are living in a parallel universe where everything is dark and gloomy. Dark Naruto and Dark Kushina could be trying to find a way to break through to the normal universe. They might encounter strange versions of their friends and foes, and have to battle their own inner demons along the way. For example, Dark Naruto might struggle with the darker aspects of the Nine - Tails' power that he has fully embraced in this universe.
It could develop in a complex way. Maybe at first, Kushina is shocked by Naruto's dark transformation. But as a mother, she tries to understand him. She might start by reaching out to him, trying to find the root of his darkness.
It's difficult to determine the popularity of this particular fanfiction. There are so many fanfictions out there in the Naruto fandom. If it has a unique and engaging story, it might be popular among those who are into darker interpretations of the Naruto characters and stories. However, it could also be relatively unknown if it hasn't been promoted well or if the theme is too niche for most fans.
Dark Naruto could be characterized as more brooding and cynical. Instead of his usual optimistic self, he might be distrustful of others due to some past betrayal. His powers might be more uncontrollable, with the Nine - Tails' influence being more prominent. Dark Kushina could be shown as a fierce and unforgiving figure. She may be highly protective of Naruto and willing to do whatever it takes to keep him safe, even if it means using extreme measures.
Perhaps the Dark Puppeteer creates illusions based on Kushina to trick Naruto. Naruto, being strong - willed, has to break through these illusions by delving deeper into his memories of his mother. He could then use the love and strength he got from Kushina to defeat the Dark Puppeteer.
One interesting plot could be that 'dark kushina' initially tries to manipulate Naruto for her own goals but gradually develops real feelings for him as she gets to know him better. Another could be that they are forced to work together to save the Hidden Leaf Village from a powerful enemy.
One interesting fanfiction could be about Kushina's untold adventures before Naruto was born. Maybe she had some secret missions that involved protecting a powerful artifact. Another could be a story where Kushina gets to train Naruto in some special and unique jutsu that only she knew. And there might be a fanfic where Kushina interacts with characters from other villages in a way that changes the whole Naruto storyline.
In 'kushina trains naruto fanfiction', it could show Kushina training Naruto in chakra control. She might use her own experiences as a jinchuriki to help him better manage the Nine - Tails' chakra. This could involve some special training exercises like meditating near the waterfall where the chakra flow is strong, which would help Naruto become more proficient in using his chakra and prevent him from going out of control when using the Nine - Tails' power.
One possible reason could be that Dark Naruto might see Kushina as a symbol of the world that rejected him. Since she was an important part of Naruto's family and the village, and Dark Naruto represents Naruto's negative emotions, he could resent her for the life he didn't have. He may feel that if Kushina had been there for him more (in his twisted view), he wouldn't have turned into this dark version.
The 'dark naruto and kushina lemon fanfiction' might be a creative take on the Naruto universe. It could be that the author wants to show a different side of Naruto, a darker side that we don't usually see in the original series. Kushina's presence could add an interesting dynamic, perhaps exploring how she would react to a son who has turned 'dark'. It might also include elements of mystery, as the readers try to figure out what caused Naruto to become this 'dark' version and how it will all play out.