His decision might give hope to other demigods. They see that it's possible to be content without striving for godhood. For example, some demigods who might have been jealous or envious of Percy could now see that there are other paths to a fulfilling life.
Perhaps he's seen the downsides of being a god in the Percy Jackson universe. Gods are often restricted by their domains and have a lot of responsibilities. Percy, who has always been a bit of a rebel, might not want to be tied down by such rules. He likes his freedom to make his own choices and help people in his own way, not in the way a god is expected to.
His friends might be relieved. They value Percy as he is, a demigod. If he became a god, he might change, and they could lose the Percy they know. For example, Annabeth might be happy that he stays a demigod because she loves him for who he is now.
Percy's death would shatter the world of those who knew him. His friends like Tyson would be inconsolable. Tyson always saw Percy as a hero and a brother. The Hunters of Artemis might also be affected. They would respect Percy's sacrifice but also feel a sense of responsibility for his death. And the gods, who had often used Percy for their own ends, might start to question their actions. Some might feel remorse, while others might fear the chaos that could follow in the wake of Percy's death, as he was often a stabilising force in the often - tumultuous world of demigods and gods.
The other characters would likely be devastated. Annabeth, his love, would be heartbroken. She might become more withdrawn and determined to avenge him. His friends like Grover would be in deep sorrow, feeling as if they've lost a part of their strength. And the whole demigod community could lose hope, as Percy was seen as a great hero.
One possibility could be that Percy, as a new god, would have to deal with the complex politics of Olympus. He's always been an outsider, and now he'd be thrust into a world of power plays and ancient rivalries. Maybe he'd try to change some of the archaic rules that the gods have held onto for centuries.
One possible reason could be that Percy values his humanity. He has seen the flaws of the gods and doesn't want to be like them. In the original series, he has had many experiences with the gods' self - centeredness. So in fanfiction, he might turn down godhood to stay true to his mortal self.
His friends would be devastated. Annabeth, in particular, would be heartbroken. Their relationship is very strong, and his death would leave a huge void in her life. She might become more withdrawn and less trusting.
The gods would have mixed reactions. Some gods who are more on the side of order and the well - being of the mortal world, like Athena, might be secretly glad that Typhon is out of the picture, but publicly they might have to condemn Percy's actions as overstepping his bounds. Other gods who are more chaotic or who had some sort of alliance with Typhon (if any) would be angry at Percy and might seek revenge. The minor gods and goddesses might feel a shift in the power balance and start to reevaluate their relationships with the major gods and the demigods.
Fanfiction expands the Percy Jackson universe by adding new characters. Writers can create demigods with unique powers or backgrounds that add more depth to the world of Camp Half - Blood.
For the other characters, Percy's death could change the entire dynamic. His leadership and strength were often relied upon. Without him, there could be a power vacuum. Some might lose hope, thinking that if Percy couldn't survive, what chance do they have? Others might use his sacrifice as a rallying point, to become stronger and more united in the face of danger. But overall, it would be a very dark and difficult time for all those who knew and cared about Percy.