It could be due to some external influence. Perhaps a powerful and evil force manipulates Artemis into thinking that Percy is a danger. This evil force might be using false evidence or illusions to deceive her. In the world of 'Percy Jackson', there are many such forces that could play such a devious role.
One possible reason could be a misinterpretation of a prophecy. Maybe Artemis believes Percy is a threat to the natural order she protects based on a wrongly interpreted prophecy. For example, if a prophecy was worded ambiguously and she thought Percy would bring destruction to the wild, she might take drastic action.
Another reason might be related to a conflict over power or territory. If Percy's actions were somehow seen as encroaching on Artemis' domain, like interfering with a sacred place of the wild that she is very protective of. His intentions might be good, but Artemis could misread them and see him as a threat to be eliminated.
One possible motive could be some sort of mind control. Maybe a powerful enemy has the ability to control Percy's actions and forces him to go after Artemis. This would add an element of tragedy as Percy would be acting against his will.
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.
One possible plot could be that the entire Greek pantheon is thrown into chaos. Percy might be seen as a huge threat, and other gods and goddesses would either try to hunt him down or form alliances with him out of fear or a desire for power. Demigods would be forced to take sides, leading to massive battles among them.
Well, it could be about Apollo's over - confidence. He might have boasted about his powers or achievements in a way that annoyed Artemis. In the context of the Percy Jackson universe, Artemis is very protective of her domain and those associated with her. If Apollo made a decision regarding something that was under Artemis' purview without consulting her, like interfering in the affairs of the hunters, Artemis would yell at him. Also, Apollo's past mistakes or actions that went against the values of the gods might be brought up by Artemis during her yelling.
One reason could be that Percy is loyal to Annabeth. In the original series, his relationship with Annabeth is strong, and he might not want to betray that for Artemis. Artemis is also a virgin goddess, which adds a layer of complexity to any potential relationship.
One possible reason could be a misunderstanding. Maybe Artemis misinterprets Percy's actions as being against her or her hunters. For example, if Percy accidentally endangers one of her hunters during a quest, Artemis might see it as a betrayal of her trust in him.
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.
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.
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.