A common theme is power and its corrupting influence. Orochimaru, in his pursuit of power, abuses Sasuke who is also seeking power. Another theme is the loss of innocence. Sasuke, who starts off as a somewhat naive boy, gradually loses his innocence due to the abuse.
The theme of survival is crucial. Sasuke has to find ways to survive Orochimaru's abuse, whether it's through his own skills or by forming secret alliances within Orochimaru's lair. This could be a major part of the fanfiction's plot as Sasuke tries to outwit his abuser.
Betrayal is also a theme. Orochimaru betrays Sasuke's trust by abusing him instead of actually helping him grow in a healthy way. And Sasuke may feel betrayed by himself for believing Orochimaru in the first place. Additionally, the theme of redemption could play a role, like Sasuke trying to redeem himself after being a victim of such abuse.
Another aspect could be the psychological impact on Sasuke. Orochimaru's abuse might make Sasuke question his own worth and his path. He could be constantly in a state of fear and self - doubt, and the fanfiction could explore how he overcomes these negative emotions and finally stands up against Orochimaru.
Power dynamics is a big theme. Orochimaru has a lot of power and knowledge, and he uses it to manipulate Sasuke. Sasuke, in turn, is trying to gain power from Orochimaru while not being completely controlled. Another common theme is the struggle between good and evil. Sasuke is on a very thin line between becoming a tool for Orochimaru's evil plans and finding his own path towards redemption or justice. Also, the theme of mentorship is there, as Orochimaru is in a sense Sasuke's mentor, but a very unorthodox and dangerous one.
The theme of redemption can also be found. Given Orochimaru's actions in the Naruto series, some fanfics might explore the idea of him finding redemption through his relationship with Sasuke. Another common theme is the exploration of Sasuke's dark side, which Orochimaru may have influenced. This can include Sasuke's moral choices and how Orochimaru's teachings play into that.
Common themes often include the idea of forbidden love. In the Naruto universe, the relationship between Sasuke and Orochimaru is complex and not exactly a typical positive one. So in yaoi fanfics, the forbidden nature of their relationship can add an element of drama and intrigue. Also, there might be themes related to self - discovery. As Sasuke and Orochimaru interact, they could learn more about themselves and their desires.
One common plot twist could be that Sasuke actually planned to be 'kidnapped' to some extent. He might have wanted to gain power from Orochimaru in a more secretive way. Another could be that Naruto and his friends discover Orochimaru's lair much sooner than expected, leading to a premature rescue attempt. And sometimes, Orochimaru may not be the real mastermind behind the kidnapping, but rather a pawn of a more powerful enemy.
A popular theme is the power struggle. Since both Sasuke and Orochimaru are powerful characters, in fanfiction, they often engage in a battle of wits and strength. For example, Sasuke might be trying to resist Orochimaru's control while she is trying to manipulate him for her own gains.
Another theme could be the exploration of good and evil. Harry is typically seen as a 'good' character, while Orochimaru is more morally ambiguous. Fanfictions might play with the idea of whether Orochimaru can be redeemed or if Harry is influenced by Orochimaru's more ruthless ways.
Common themes include Orochimaru's curiosity about Hinata. Given his scientific and power - hungry nature, he might be intrigued by Hinata's abilities. Also, there could be themes of danger and protection. Hinata could be in danger from Orochimaru's schemes, and then other characters might come to protect her. It's also possible to see themes of transformation, where Orochimaru's influence causes Hinata to change in some way, or vice versa.
One common theme is power dynamics. Orochimaru is a very powerful character in the Naruto universe, and in harem fanfictions, there can be a play on how his power affects his relationships with the other characters in the harem. Another theme could be redemption. Sometimes, the fanfiction might explore Orochimaru's journey towards redemption through his interactions with the harem members.
One common theme is power and ambition. Since Orochimaru is known for his pursuit of power, the OC often gets caught up in that. Another is the exploration of the dark side of the ninja world. Orochimaru is a rather dark character, so the OC may have to deal with moral gray areas. And there's also the theme of self - discovery. The OC in these fanfictions usually has to figure out who they are in relation to Orochimaru and the world around them.