Well, in a fanfiction, it could be possible if Orochimaru has a change of heart. Maybe Naruto's unwavering belief in redemption reaches Orochimaru. Naruto is known for seeing the good in people, and he might be able to convince Orochimaru to turn away from his dark ways. This new - found friendship could lead to Orochimaru using his vast knowledge for the good of the village, like helping with medical research or sharing his knowledge of forbidden jutsus in a more ethical way.
In a fanfiction scenario, it could happen if there was some sort of shared goal. For example, both Naruto and Orochimaru might want to take down a greater evil that threatens the ninja world. They could put aside their differences and form an alliance which could gradually turn into a friendship. Naruto could learn a lot from Orochimaru's intelligence and Orochimaru could be influenced by Naruto's positive energy.
It could be possible in a fanfiction if there was a rewrite of their past interactions. What if Naruto had met Orochimaru at a different time, before Orochimaru had fully embraced his dark path? Naruto's friendly and outgoing nature might have rubbed off on Orochimaru, and they could have become friends. This would change the entire dynamic of the Naruto story, with Orochimaru potentially becoming a mentor - like figure to Naruto in some aspects.
A possible plotline could be Orochimaru's redemption. He realizes the error of his ways and joins Naruto in protecting the ninja world. He could use his vast knowledge of jutsu and forbidden arts to help Naruto against new threats.
One possible reason could be in the realm of artistic interpretation in the fanfiction. The author might want to explore a different aesthetic or a unique plot where Naruto has some physical or behavioral traits similar to Orochimaru for shock value or to create a new kind of character dynamic.
They could be related as adversaries with a strange connection. In fanfiction, Orochimaru might be after Naruto not just for the Nine - Tails, but also because Naruto has something that Orochimaru lost long ago. This creates a complex dynamic where they are constantly at odds, but there is also a deeper underlying connection.
Another possible motive is that Orochimaru sees Naruto as a potential powerful ally or tool. Naruto has shown great potential and growth throughout the series. Orochimaru could think that by taking Naruto and molding him in his own way, he could have a powerful weapon at his disposal. He might also want to use Naruto to get back at Konoha in some way, since Naruto is one of Konoha's most important assets.
The overall theme of the fanfiction could change. If Naruto absorbs Orochimaru, the story could start to explore themes like the nature of power and corruption more deeply. It might also delve into how Naruto can use Orochimaru's power for good, rather than succumbing to the evil associated with it. This could make the fanfiction more of a moral exploration within the Naruto universe.
He could develop post - traumatic stress disorder (PTSD). Flashbacks of the torture might haunt him during battles or normal daily activities. This would not only affect his performance as a ninja but also his personal relationships. Naruto might become withdrawn as a result of the torture. He might isolate himself from his friends and the village in an attempt to protect them from any potential harm that could come his way because of his association with Orochimaru through the torture. This isolation would further damage his mental state as he thrives on the support and friendship of those around him.
Sakura would be worried sick. She might immediately inform Kakashi sensei and the rest of the village. Then, she would probably want to be part of the rescue mission. Sakura has grown stronger over time and would use her medical ninjutsu and combat skills to help save Naruto. She would also be constantly worried about Naruto's well - being and would encourage the others to move faster.
In this type of fanfiction, it might also be that Naruto joins Orochimaru to spy on him. The Hidden Leaf Village realizes they need to know Orochimaru's plans from the inside. Naruto, being the brave and somewhat reckless one, volunteers for the mission. He endures Orochimaru's experiments and teachings while secretly sending information back to the village. Eventually, when the time is right, he betrays Orochimaru and uses the knowledge he gained against him.
One possible plotline could be Naruto being forced to serve Orochimaru due to some sort of blackmail or threat against his friends in Konoha. Maybe Orochimaru has some information that could endanger Naruto's loved ones if he doesn't comply. Another aspect could be Naruto initially pretending to serve while actually trying to find a way to take Orochimaru down from the inside. This would add an element of mystery and deception to the story.
Perhaps Naruto starts to have a connection to Orochimaru's other experiments or creations. He might find himself in a situation where he has to either help or fight these other 'products' of Orochimaru's mad science. Also, the fanfiction could explore how Naruto's friends react to what has happened to him. Do they trust him still? Or are they afraid of what Orochimaru might have turned him into?