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.
The story could focus on the search for a new hero. The vacuum left by the retiring hero might create a need for someone to step up. This could lead to a whole new plotline about finding and training a worthy successor.
Perhaps there are some pre - arranged plot settings in the light novel. The author wants to create a sudden and romantic plot point to attract readers. It might be related to some prophecies or hidden plot threads that have been gradually revealed throughout the story, leading to this sudden proposal.
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 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.
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.
In 'the hero proposed to me light novel', themes such as destiny or fate might be present. Maybe the story implies that they were meant to be together, and the proposal is a culmination of that. Additionally, the theme of courage could be there. It takes courage for the hero to propose, and perhaps the protagonist also has to be brave to accept or reject the proposal, which can explore different aspects of their personalities.
One possible reason is that the lupus has been deceived. If someone has tricked the lupus character, they might scold out of anger.
Perhaps the hero's values changed in a way that the society in the novel didn't accept. He might have started with noble intentions but as the story progressed, he became self - centered or greedy. This transformation would make the other characters in the novel, and even the readers, view him as a failure.
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.