Perhaps there is a fellow slave or a sympathetic free person in the novel. This character could play an important role in the slave girl's journey, either by providing support, friendship, or a different perspective on her situation.
As I don't know the story, I can't tell for sure. But likely, the slave girl herself is a main character.
One main theme could be oppression. In the 'the slave girl novel', it might show how the slave girl endures various forms of oppression, like being deprived of basic rights and freedoms. Another theme could be survival. She has to fight against the harsh conditions to stay alive.
Since I haven't read 'slave to the darkness novel', I can only speculate. There could be a protagonist who is forced into this state of being a slave to darkness. Maybe there is a mentor - like figure who tries to help the main character break free, or there could be other characters who are also trapped in the same situation and they bond over their shared plight.
Obviously, the boy slave himself is one of the main characters. He is the central figure around whom the story revolves. There may also be the slave master, who represents the oppressive force in the boy's life.
Since I haven't read the 'slave to darkness novel', it's hard to say for sure. However, the main characters might include a protagonist who is on a path to self - discovery while being a slave to darkness. There could also be an antagonist representing the pure essence of the dark power that controls the slaves. And perhaps there are other supporting characters who are either fellow slaves or those trying to free the slaves from the clutches of darkness.
Slave girl comics often depict themes of powerlessness and exploitation. The characters might face harsh conditions and have limited control over their lives.
Slave girl cartoons often depict characters in vulnerable situations and may focus on themes of power, oppression, and escape.
One main theme is oppression. The slave girl endures the hardships and restrictions placed on her by the system of slavery. Another theme is hope. Despite her difficult situation, she may hold onto the hope of a better life, either through freedom or some form of improvement in her circumstances.
Slave girl comics often feature themes of oppression, power dynamics, and the struggle for freedom. The characters might face various hardships and challenges.
Since I haven't read this particular web novel, it's hard to say exactly. However, based on the title, the main character is likely the shadow slave. There could be other supporting characters like fellow slaves who are in the same situation, or maybe a mentor - like figure who helps the shadow slave discover their potential. There could also be characters from the upper echelons of the society in the story's world, who either oppress or are intrigued by the shadow slave.