Vargas's Past — "The boy who had no choice but to become the Demon King" Vargas was born as the son of the Demon King. However, his father was not a tyrant who ruled over demons, but a king who desired peace with humans. On the day of the peace negotiations, the humans entered the Demon King's castle under the guise of a "token of alliance" and attacked the meeting site. Vargas was hidden by his mother and could only watch. His father never drew his sword until the end. "If this ends the war..." Those were his father's last words. But the war did not end. Instead, the humans promoted themselves as heroes who defeated the Demon King and began invading demon territory. Eventually, Vargas's identity was discovered in the village he fled to. The villagers did not protect him. "If we shelter the son of the Demon King, we'll be killed too." Saying so, they handed him over. Just before he was to be executed, Vargas manifested the black flames for the first time. From that day on, he decided, "I will never trust anyone again."

Selene's Past — "The Silver Witch" Selene was born to a human mother and a demon father. Her mother loved her. Her father loved her too. That is why the two of them lied to protect Selene. In the human village, her mother kept saying, "This child is a normal human." In the demon country, her father kept saying, "That child does not have a drop of demon blood." However, Selene's magic power was far too strong. The villagers feared her. The demons also looked down on her as an "incomplete being with mixed human blood." Then the war began. Her parents tried to let only their daughter escape. Selene fled into the forest. When she looked back, her house was burning in the distance. She never found out what happened to her parents. She only learned much later. It was made to look like the parents had betrayed each other. To the humans, she was told as, "A woman deceived by a demon man." To the demons, he was told as, "A man who sold his soul to the humans." Even though the two had protected each other until the very end.

And then, the two meet. Years later. They met on the battlefield. Vargas looked at Selene and said, "You have the face of someone who was abandoned by someone, too." Selene replied, "As do you." Both realized the other was just like them. But— There was an even more sickening truth. The war that took their parents. The powerful elites on both the human and demon sides who started it actually had no intention of making peace from the beginning. If the war continued, weapons and food would sell. Territory would increase. So the upper echelons of both nations continued to lie, claiming the "enemy betrayed the peace." Vargas's father. Selene's parents. Thousands of people. They all died for the convenience of those in power. And the two of them learned that fact. That is why Vargas became the Demon King. Selene became the Demon Queen. Not for revenge. "To create a country where we never lose the people we love for someone else's convenience again." However, the two still have one regret. When they first met on the battlefield— If they had known each other's identities, they would have fought as enemies. The reason the two can stand side-by-side as a couple now was only because they were a little bit lucky. Nevertheless, the love between them is real.