One possible reason could be that Percy has shown great courage and a pure heart. Artemis might see in him the potential to be a great ally in the fight against the forces of chaos. Maybe Percy has also done something to earn her respect, like saving one of her hunters or standing up for what's right in a situation that involved her domain.
Maybe there's a scene where Percy is in danger from a powerful monster, and Artemis steps in to defend him. She could use her hunting skills or her divine powers to fend off the attacker.
One possible reason could be a misunderstanding. Maybe Percy accidentally disrupted one of Artemis's hunts or sacred rituals in the fanfic. Another reason might be that some prophecy or fate in the fanfic's made - up world has pitted them against each other. For example, if there's a prophecy that Percy's actions will somehow limit Artemis's power or freedom in the future.
One possible reason could be differences in their divine natures. Percy is a son of Poseidon, a god associated with the sea and a more fluid, emotional element. Artemis is a virgin goddess of the hunt, very strict and unyielding in her ways. This contrast in their essences might lead to clashes and Percy's dislike.
Well, perhaps in this fanfiction, Artemis betrays Percy for Orion due to a prophecy. There could be a prophecy that states that Orion and Artemis together will bring about some great change or prevent a huge disaster, and Artemis believes she has to choose Orion over Percy to fulfill it. Also, Orion might have some sort of leverage over Artemis that forces her to turn her back on Percy.
One possible reason could be a misunderstanding. Maybe there was some miscommunication or false information spread that made Artemis think Percy had done something unforgivable. For example, if Percy was wrongly accused of harming one of Artemis' beloved creatures or desecrating her sacred places.
It might be due to the way their goals are presented in fanfiction. Naruto is often about protecting his village and friends. If Artemis's goals in the fanfic are in conflict with Naruto's, like if she's more focused on her own self - interest in the story, Naruto would hate her.
Well, perhaps there's a power struggle in the mythological world. Some powerful being wants to control or manipulate Percy, and they see Artemis as a means to an end. By forcing Percy to stay with her, they can keep an eye on him or use Artemis's power and influence to their advantage. It could also be that Percy has unknowingly stumbled upon a secret or a power that is related to Artemis, and to protect it or study it further, he is made to stay with her.
It could be due to a lack of information. Artemis might not have known all the facts about Percy. For instance, if there was some sort of illusion or false information spread around, she could have misjudged the situation and accidentally killed him. Also, perhaps in the heat of a battle, she didn't have time to properly identify her target and made a tragic mistake.
Percy could lose trust in the gods completely. After Artemis' betrayal, he might feel that he can't rely on any of them anymore.
In some fanfics, it could be a competition gone wrong. For example, a friendly sparring match between Percy and Artemis turns into a full - fledged fight due to some external interference like a magic spell or a cursed weapon. This could lead to a series of events where they have to put aside their differences and work together to solve the problem that caused the fight in the first place.