Well, it could lead to a plot where Naruto is constantly on the run from Orochimaru's minions who want to take advantage of the mark. For example, they might try to use it to control Naruto or extract some sort of power from him.
In the fanfiction world, 'Marked by Orochimaru: Naruto's Struggle' might exist. The mark could potentially change Naruto's relationships with his friends. Some might be afraid of him because of the mark's association with Orochimaru. Naruto, on the other hand, would strive to prove that he's still the same person and not be defined by the mark.
Well, one possibility is that Naruto could gain a much darker and more ruthless fighting style. Orochimaru might teach him some forbidden jutsu that are not part of the regular Konoha training. Naruto could also struggle with the moral implications of being trained by such a villain. For example, he might question whether using Orochimaru's methods to protect the village is the right thing to do.
Well, the plot could involve Naruto being trained in Orochimaru's lair. He'd be exposed to Orochimaru's experiments and might gain some unique powers from them. For example, he could have better control over snakes or learn some snake - based jutsu. His view of the ninja world might also be warped as he grows up in Orochimaru's influence, seeing things more from a survival - of - the - fittest perspective.
A 'naruto trained by orochimaru fanfic' might have Naruto delving deeper into the secrets of the Sharingan. Orochimaru has always been interested in the Uchiha's power. So Naruto, under his training, could be exposed to knowledge about the Sharingan and its potential. This might lead to some interesting power - ups for Naruto, but also put him in the crosshairs of other powerful ninja who are also interested in the Sharingan's secrets.
It would be a huge deviation from the original Naruto character. It would mean Naruto giving up on his values of friendship and loyalty. Instead of protecting the village and its people, he would be more interested in personal gain and power, like Orochimaru. His relationships with his friends like Sasuke and Sakura would be completely different, probably full of mistrust and manipulation.
In a fanfiction where Naruto is adopted by Orochimaru, Naruto's development would take a very different turn. Orochimaru could train Naruto to be more ruthless in combat. However, Naruto might also resist Orochimaru's darker intentions. This internal struggle could be a major part of the story. Naruto might try to find a way to use Orochimaru's knowledge for good, while still holding onto his own values. He could also face discrimination from other ninjas who see him as Orochimaru's apprentice and therefore a potential threat.
In fanfiction, if Naruto were trained by Orochimaru, he might gain some very dark and powerful jutsu. Orochimaru is known for his unethical experiments and forbidden jutsu. Naruto could become a more morally ambiguous character, as Orochimaru's influence might taint his usually positive and straightforward nature. His power level would likely skyrocket, but at the cost of his relationships with his friends in Konoha who might be wary of his new, darker abilities.
If Naruto were to join Orochimaru in fanfiction, it would be a huge deviation from the original story. Naruto's values of loyalty and friendship would be put to the test. He might start to see the world from Orochimaru's perspective, which is often self - serving. This could also mean that Naruto would be involved in Orochimaru's plans to gain immortality, perhaps even becoming a part of his body - swapping experiments in some extreme cases.
In this fanfiction, their relationship could be full of tension. Orochimaru is a character who often pursues power through unorthodox means. Naruto, on the other hand, values life and friendship. So, they would constantly be at odds. But at the same time, there would be a sense of loyalty between them as brothers. Orochimaru might try to manipulate Naruto at times, while Naruto would be trying to redeem his brother, leading to a very tumultuous relationship.
In a fanfiction like this, the plot might involve Orochimaru having some hidden motives in becoming Naruto's 'mate'. Maybe he wants to use Naruto's connection to the Nine - Tails to gain more power for himself. But as time passes, Naruto's positive influence starts to change Orochimaru in ways he didn't expect. Naruto, on the other hand, might see Orochimaru as a project, someone he can reform, and this idea of reforming him could be the basis of their relationship in the fanfiction.