Artemis' twin brother Apollo could be quite amused at first. He might tease Artemis about it. But then he could also see the potential in Percy and help him out in some ways, just to stir things up. The nymphs who are associated with Artemis' domains might be worried. They fear that if Artemis gets involved with Percy, it could change the way she manages her territories. But they also trust Artemis to make the right decision in the end.
In this fanfiction, perhaps Percy would have to overcome many challenges. Artemis is a maiden goddess, so she might initially be very hesitant. Percy could start by showing his deep understanding of her values, like her love for nature and the hunt. He might bring her unique gifts related to these aspects. And he would need to convince her that their relationship could work, despite the differences between a demigod and a goddess.
Harry would probably be extremely shocked. He has a deep respect for both Hermione and Severus in different ways, and this situation would completely turn his world upside down. He might initially be angry or confused, but then try to understand what led to this. Ron, on the other hand, would likely be more openly outraged. He has always had a bit of a jealous streak when it comes to Hermione, and this would be a very difficult situation for him to accept.
Fans could have mixed reactions. There would be those who firmly oppose it, as they see it as a violation of the essence of the characters. They might stop reading the fanfiction altogether. On the other hand, a certain group of fans, especially those who enjoy exploring the darker side of fictional worlds, might find it an interesting concept. They could engage in discussions about how this could change the overall perception of the Percy Jackson universe.
The other characters would likely be filled with grief. His friends would probably feel a deep sense of guilt, wondering if there was something they could have done to stop him. Artemis herself might feel a heavy burden, knowing that Percy sacrificed his life for her. She may vow to honor his memory in some way.
The hunters of Artemis might be caught in the middle. They respect Artemis but also might see Percy as a valuable ally. So, they could be torn between trying to appease Artemis' jealousy and maintaining a good relationship with Percy. For example, some hunters might distance themselves from Percy to avoid Artemis' wrath.
Ginny might be shocked at first. Given their past as rivals, it would be quite unexpected. She might need some time to think about it. Her friends, especially the Gryffindors, would probably be very surprised too. Some might be against it due to their old views of Draco. But others might see the change in Draco and be more open - minded.
A centaur who has knowledge of ancient prophecies involving both Percy and Artemis could be added. The centaur could act as a guide or a mentor to them during their adventure. He could provide crucial information about the enemies they are facing and how to use their combined powers effectively. For example, he might know of a weakness in a powerful foe that only Percy's unique abilities and Artemis' lunar powers can exploit.
The centaurs from Camp Half - Blood could be allies. They are wise and have a long history of helping demigods. Their knowledge of ancient prophecies and combat techniques could be useful to the Son of Artemis. Additionally, some of the minor gods' children might side with him. For example, the children of Hecate could use their magic to help him in difficult situations. They might see the Son of Artemis as a symbol of change in the demigod world and want to support that. Nico di Angelo, with his powers over the Underworld, could also be an ally. He could offer protection from the darker forces that might target the Son of Artemis.
Some characters might be shocked at first. They are used to seeing Percy in his normal way of dressing, so this sudden change would be unexpected.
Well, for starters, Artemis would probably be in shock. She's a goddess, not used to being saved in such a drastic way. She might become more protective of the demigods as a result. As for Percy's friends, they'd be angry too. Angry at the situation that led to his death. They might question why Percy had to be the one to sacrifice himself. And the younger demigods would look at Percy's death as a very solemn event, a reminder of the risks they all face. It would be a very dark time in the demigod community.