Redemption and forgiveness play a part as well. The actions that led to one being a prisoner and the harm caused may need to be forgiven. The characters may go through a journey of understanding each other's motives and finding a way to move forward from their past actions, especially in the context of the war.
Survival and hope are also prevalent themes. The war prisoner often has to fight for his survival in a difficult situation, and the relationship with the other character can become a source of hope. In some novels, they rely on each other to get through the tough times in the prison or war - affected area.
One common theme is the struggle against oppression. War prisoners face the power of their captors and have to find ways to resist, whether it's through small acts of defiance or grand escape plans. Camaraderie is also important. They form bonds with their fellow prisoners to support each other through the tough times. And there's the theme of identity. Being a war prisoner can change a person's sense of self and how they are perceived by others.
Survival is a very common theme. The prisoners have to find ways to stay alive in harsh conditions. Another theme is hope. They hope for rescue or for a change in their situation. And also, the theme of camaraderie among the prisoners is often explored as they support each other through the tough times.
One common theme is comradeship. In a Prisoner of War story, the prisoners usually rely on each other. They share resources, protect one another, and boost morale. For example, they might take turns standing guard at night to protect against the guards' sudden attacks. Another theme is adaptation. They must adapt to the new and often terrible environment, like learning to eat strange or unappetizing food to stay alive. And then there is the theme of the will to freedom. It drives them to plan escapes or endure until they are released.
The theme of power dynamics is quite common too. The relationship between the captors and the captives involves a complex web of power. The captors have the physical power to control the prisoners, but the prisoners may have some form of psychological or moral power. This struggle for power and control is often explored in these light novels.
Betrayal can be a theme as well. There could be situations where prisoners are betrayed by their own side or by other prisoners. This adds to the complexity and drama of the story. Also, redemption can be part of the story. A character who has made mistakes might find a way to redeem themselves while being a war prisoner.
One popular 'war prisoner' BL novel could be 'The Mercenary's Prisoner'. It tells a story of a captured soldier and his relationship with the enemy who holds him captive. The story is full of tension and emotional development between the two main characters.
The theme of forbidden love often appears. Since it's BL, in a horror context, the love between the two male characters might be seen as something that goes against the norm in the spooky world they are in. Maybe there are forces trying to keep them apart because of their relationship, which adds an extra layer of drama and horror to the story.
Power dynamics also play a role. There could be a dominant and a submissive character, which adds an extra layer of tension and excitement to the relationship. This can be seen in novels where one character is in a position of authority, like a CEO or a senior in a school, and the other is more inexperienced.
One common theme is self - discovery. The transmigrating character often has to figure out who they are in a new world and how they fit in. For example, they might discover new abilities or aspects of their personality. Another theme is the changing of fate. They try to change the original plot, especially when it comes to the fate of the male love interest.
One common theme is the power imbalance. Since vampires are often depicted as more powerful than humans, in a BL context, this can create an interesting dynamic between the two male characters. Another theme is the struggle with identity. The vampire character may be struggling with his vampiric nature while also dealing with his feelings for the other male character.