A plot could revolve around their son being born with a rare illness that Sakura, despite her great medical skills, is unable to fully cure. This leads to a search for a cure across different lands. Naruto, being the Hokage, has to balance his duties with helping his son. Their son, in the meantime, shows great courage and determination, not wanting to be a burden. He trains hard to become strong enough to face whatever comes his way, and along the journey, they encounter many challenges and make new friends who join them in their quest for a cure.
A plot might be that Naruto is born in the Naruto universe but has dreams and visions of Sparda. As he grows, he starts to show extraordinary powers that are not normal for a ninja. He then embarks on a journey to find out who Sparda is and discovers that he is his father. Along the way, he meets characters from the Devil May Cry universe who help him understand his powers. He has to fight against ninja clans who want to use his powers for their own gain and demons who want to corrupt him. He uses his Naruto - like tenacity and Sparda - inspired powers to overcome all these obstacles.
One possible plot could be that Kakashi discovers Naruto is his son in a surprising turn of events. Maybe there was some hidden truth about Naruto's birth that was concealed all this time. Kakashi then has to deal with the newfound father - son relationship while also guiding Naruto in his ninja training. He could be more protective and pass on some of his unique skills more intimately.
In some fanfics, Naruto may ignore Sakura because he has his own emotional traumas to deal with. He might find Sakura's presence a reminder of things he wants to forget or move past, so he chooses to keep his distance. For example, if he has faced a lot of rejection from her in the past, he could decide to just cut her out of his life.
One possible reason could be that Naruto has his own goals and missions that he is so focused on that he tries to avoid distractions, and Sakura might be seen as a distraction in some sense. For example, he is always aiming to become Hokage and improve his ninja skills, and any personal relationship drama could get in the way of that.
Another development could be that Sakura starts to develop feelings for Naruto as she spends more time thinking about his love for her. She might notice things about him that she never paid attention to before, like his kindness and determination in a more romantic way.
One possible plotline could be Sakura having to overcome her blindness while still training as a ninja. Maybe she develops new skills that rely more on her other senses. For example, her sense of smell or hearing could be heightened to detect enemies or find her way around.
It could also be that Naruto is forced to leave Sakura due to some external threat or danger. For instance, if there is an enemy targeting Naruto and he fears that being around Sakura will put her in harm's way, he would choose to leave to keep her safe. This is in line with Naruto's selfless nature as seen throughout the series.
One possible plot twist could be that the second Hokage had some secret enemies who target Naruto because of his lineage. Another could be that Naruto discovers some hidden jutsu or power that was passed down specifically from the second Hokage. Maybe there's a twist where the village initially rejects Naruto because they believe the second Hokage had some dark secrets that they fear Naruto might inherit.
I'm not aware of any official 'naruto enslaves sakura fanfic' as it goes against the positive themes of the original Naruto series. Fanfics with such disturbing concepts are not in line with the spirit of the show which promotes friendship, growth, and respect among characters.
In this kind of fanfic, one possible reason could be unrequited love. Naruto might have felt so hopeless about his feelings for Sakura never being returned that he saw no way out. He had always been in love with her, and if she continuously rejected him and perhaps even chose someone else, it could have broken his spirit to the point of self - destruction.