Based on this song: https: //youtu.be/WX13s_H8X5c

Here we see Alaska in the past. He was listening to his father shower Dorin, his younger brother, with a lot of affection. Their father never really gave Alaska as much affection while he was growing up. Most likely because he was illegitimate and couldn't be the heir to the throne. Instead he was trained to be a guard captain.

All Alaska wanted was equal affection from his parents, but Dorin was getting most of it. This lead to Alaska becoming more and more jealous over time until the fateful day where he became corrupted.