In this kind of fanfic, Naruto might be in a really tough situation. Orochimaru could be after his chakra or some secret power within him. Maybe Naruto will try to use his shadow clones to escape or call for help using his toad summons.
One possibility is that Orochimaru wants to use Naruto to get to Sasuke. Since Sasuke was once Orochimaru's apprentice and Naruto is Sasuke's close friend. Naruto might resist and start to learn new jutsus while being held captive to fight back.
It's also likely that Naruto's friends will notice his disappearance quickly. Sakura, Kakashi, and the others could start a rescue mission. They would face many challenges on their way to Orochimaru's lair as Orochimaru has many traps and minions to protect himself.
Well, in such a fanfiction, Sasuke might be taken to Orochimaru's lair. There, Orochimaru could try to force Sasuke to accept his power - like the cursed seal. Sasuke, being strong - willed, would likely resist at first. But Orochimaru has his ways of persuasion. Maybe he'd show Sasuke some dark jutsu that could make Sasuke more powerful. And Sasuke, who's always eager to gain power to avenge his clan, might start to consider Orochimaru's offer despite the risks.
Well, Naruto might use his Nine - Tails chakra to break free. He's a tough one. He could also try to outwit Orochimaru with his ninja skills. Maybe he'd pretend to be unconscious and then surprise Orochimaru when he least expects it.
Naruto getting kidnapped by Orochimaru would be a really dangerous situation. Orochimaru could start by putting Naruto in some sort of chakra - suppressing device. This would limit Naruto's ability to use his Nine - Tails power. Then, he might try to implant some of his cursed seals on Naruto, which would give him more control over Naruto. But Naruto has his own allies within himself. The Nine - Tails, despite their rocky relationship, might help Naruto out in this situation. Also, Naruto has the memories of all the people who care about him. He'd draw strength from those memories and keep his hope alive, waiting for the moment when he can break free and return to his friends and the village.
Perhaps Naruto goes to Orochimaru in an attempt to redeem him. Naruto has a strong belief in the good in people, and he might think that he can convince Orochimaru to stop his evil ways. He could offer Orochimaru a chance at redemption, like a new start in the Hidden Leaf Village if he gives up his dark experiments and ambitions. This would lead to a complex relationship development between them, with Orochimaru being skeptical at first but gradually considering Naruto's offer.
Another scenario could be that Naruto discovers a hidden chamber in the lab. Inside, there are test subjects that Orochimaru was using for his immortality experiments. Naruto feels sympathy for them and tries to rescue them. However, he has to figure out how to deal with the various traps and security measures in the lab first. He might call for help from his friends like Sakura or Kakashi to assist him in this difficult task.
Naruto might learn some very dark and powerful jutsus. Orochimaru is known for his forbidden jutsu knowledge. So Naruto could become a much more dangerous fighter but also risk being influenced by Orochimaru's immoral ways.
In a scenario where Orochimaru kidnaps Hinata, the Hyuga clan would surely get involved. They'd be outraged and use all their resources to find her. Orochimaru might be interested in Hinata's Byakugan for his experiments. He could try to extract its power or study it. But Hinata has been trained in the Gentle Fist style, so she might be able to hold her own against Orochimaru's minions for a while. And who knows, Sasuke might also get involved. He has his own history with Orochimaru and might see this as a chance to confront him again, especially if he realizes that an innocent like Hinata is in danger.
In such a fanfiction, Sakura might be used by Orochimaru for his experiments. He could be interested in her chakra or her medical knowledge. Maybe he would try to extract some special power from her or force her to assist him in his unethical research.
It could go in a different direction too. Naruto might reject Sakura's confession. He could still see her as a dear friend, but not in a romantic way. This would create a lot of tension between them, and Sakura would have to deal with the heartbreak. Meanwhile, Naruto would have to figure out how to keep their friendship intact despite the awkward situation.
One possibility is that Naruto's revival by Madara could lead to a power shift in the ninja world. Naruto might have new and unexpected powers upon his return. Maybe he could combine his own abilities with some of Madara's knowledge or techniques.