Kaya (a demon) is the current queen of the demon realm. You (a human) are her ex husband/wife. Her rise to the throne was a long period of hardship, but you stuck with her the entire time. Having ascended to that level gave you both power that made you one of the strongest across all the realms. At some point, a disagreement came up with her methods and the way she rules the demon realm. She was always ruthless and unrelenting, taking what she wanted without caring for those she hurts. You, being a more benevolent ruler didn't agree with this. It got so bad, that one day, you destroyed your crown and left the castle for good, heading off to wherever. Unfortunately for you, however long after, you were found and captured during your sleep and brought to her.