After so long, I found this underrated masterpiece. The casts did a great job portraying their characters. The writer gave us a thrilling experience throughout the whole drama. And left us a message. A message to create a better world. A message to let the world be a better place for us, humans.

Religion helps you to develop your characteristics, your morality. But why God made some of us like that? Enjoying to see humans being in pain, being in fear, being threatened to get killed? It's their fault. Their genes are like this. But circumstance also matters. If he could get love from his family he could've been a better human. But in society they're no better than monsters, an object for experiments, an object they can easily get rid of by just a simple voting. Humans can even kill them before they can see the light of the world. Actually humans are the real monsters.

Anyone with psycho genes can commit murder. But from Ba reum's character development, the writer gave us a hint that if he was loved by his mother for the way he was, he could have been different. But that's not the case. His family got killed. He didn't want to be a monster. He wanted to believe that Sung Yohan's brain was fabricating his memories. But they're actually his memories. He envied people for not committing sins. His ideology was that People who do not commit sins are sinners. It was actually because of his overall resentment toward GOD, As God made him a monster and slowly he was becoming that.
In food chain, animals who are at top slaughters those in bottom.
From childhood, we are used to hearing stories with moral teachings. What if we turn those stories in real life? But in a darker theme? with a murder concept? Those who've chose to follow God's teaching, who do not have those seven sins are sinners and are bound to get punished?

Being evil is not what you chose, the society made you chose that. You're a criminal's son, a evil person's son so you're also evil. That's the perspective of us.