It could potentially be a cursed ninja from a rival village. They might target Naruto thinking he's an easier target than Sasuke, or perhaps they have some vendetta against Naruto specifically. This would lead to a situation where Naruto has to deal not only with the effects of the bite but also the threat from this cursed ninja and their village.
It could be a powerful enemy like Orochimaru. Orochimaru was always interested in Sasuke's potential, but if the plot changes and Naruto gets bitten, Orochimaru might see Naruto as an equally interesting subject to experiment on.
Maybe it's a new, unknown creature or demon in the fanfic world. This would open up a whole new storyline. The creator of the fanfic could design this new entity to have specific motives for biting Naruto, like trying to steal his chakra or use him as a vessel in a different way than what was seen in the original Naruto series.
Another possibility is that it could be a cursed or possessed person. They might not be in control of their actions and end up biting Naruto. This could be part of a larger, darker plot where a curse is spreading and Naruto becomes an accidental victim instead of Sasuke.
In such a fanfic, Naruto might gain some unique abilities from the bite. Maybe it would change his chakra nature or give him a new form. It could also lead to a different relationship with the creature that bit him. For example, if it was a demon, he might have to deal with its influence in a new way compared to Sasuke.
Well, if Naruto gets bitten instead of Sasuke, it could lead to a whole new set of powers for Naruto. Maybe he'd gain some sort of dark or unique ability that changes his fighting style. It could also change his relationship with other characters. For example, his friends might be more worried about him and try to find a way to cure him. And his enemies might see him as an even greater threat or a new target.
In such a fanfiction, it could lead to a completely different power dynamic within the ninja village. Maybe Naruto's absence would give rise to new challenges and characters stepping up.
Kakashi might also side with Naruto in this scenario. He has trained Naruto and has a deep bond with him. If Kakashi discovers that Naruto has been wronged, he could choose to follow Naruto rather than the village's orders. Additionally, Hinata might be an ally. Her love for Naruto could make her stand by his side, believing in his good nature no matter what the village says.
One possible plot could be Naruto feeling betrayed by the village. Maybe he discovers some dark secrets about the Hidden Leaf that make him question his loyalty. For example, if he finds out that the village leaders were involved in unethical experiments. So, instead of following the village's rules blindly, he goes rogue to seek his own version of justice.
One possible plot development could be Naruto leaving to find a way to prevent Sasuke from ever wanting to leave in the first place. He might embark on a journey to discover the root cause of Sasuke's hatred and try to resolve it from afar. This could lead to Naruto meeting new characters who have insights into the Uchiha clan's past and Sasuke's state of mind.
Maybe in the fanfiction, Naruto's positive and energetic personality attracts Ino more. He is always so full of life and has a big heart.
Well, there could be a plotline where Naruto, under Kakashi's training, discovers a new power within himself that was previously untapped. This new power could draw the attention of powerful villains outside the village. Meanwhile, the relationship between Naruto and Sasuke would also change. Since Naruto is getting better training, Sasuke might feel jealous or motivated to find a different kind of training. This could lead to a more complex dynamic between them, different from the original story.
Well, Naruto has a very warm and persistent personality. He's always there for his friends, and he has a big heart. In fanfiction, Sakura might see these qualities in Naruto and realize his true value. He's the kind of person who can make her laugh and feel safe, which could be very appealing compared to Sasuke's more brooding nature.