Another possibility is that his death is part of a tragic plot device. It might be used to create a sense of pathos and make the story more memorable. For example, his death could be due to a misunderstanding that couldn't be resolved in time, leaving the heroine heartbroken.
One possible reason is a misunderstanding. The hero might think that they are in love with the person they marry, but later find out it was all a mistake. For instance, they might have misinterpreted their feelings of friendship or gratitude as love. Also, external threats could be a factor. If there is a threat to the hero's family or community, they might marry someone else as a way to protect them.
One possible reason could be a misunderstanding. Maybe the hero misinterprets the heroine's actions or words and lashes out with an insult.
One possible reason could be a misunderstanding. Maybe there was some miscommunication in the past that led the hero to form a negative opinion of the heroine. For example, he might have overheard something that was misinterpreted.
One possible reason could be that the hero has a bad reputation in the society they live in. Maybe he is known for being a playboy or having a cruel streak, which makes the heroine despise him.
Perhaps the hero hides her out of jealousy or possessiveness. The result might be a lot of drama and misunderstandings before they finally work things out.
One possible reason could be a broken heart. If she was deeply in love and got rejected or betrayed, the emotional pain might be too much to bear. For example, in some stories, the girl loves a guy who turns out to love someone else, and she becomes so devastated that she loses the will to live.
One reason could be that he thinks they are too unrealistic. Heroine novels often have elements of fantasy and over - the - top romance, which might not appeal to his more practical or down - to - earth nature.
Perhaps he is tired of the constant danger and stress. Being a hero often means facing life - threatening situations regularly. After years of this, he might just want a peaceful, normal life away from all the chaos. For example, he might long for a simple life like farming or fishing, where he doesn't have to worry about the next big battle.
There are several possible reasons. Firstly, for the sake of drama. It makes for a very intense and emotional story when a beloved character like Percy dies. Secondly, it could be to explore the after - effects on the other characters. How would Annabeth cope? How would the Camp Half - Blood react? Also, it might be a way to show the unforgiving nature of Tartarus.
There could also be some sort of genetic or pre - existing condition that the baby has. In the fanfiction world, the mpreg concept may come with its own set of genetic anomalies. If these are not properly addressed or monitored in the nursery, it could lead to the baby's death.