King Sombra originally was just a normal unicorn, who came to the Crystal Empire, to study the power behind the Crystal Heart. While his observation he became close friends with the queen of the Empire. When the queen realized that Sombra’s studies started to take a dark turn (as he started to study how the Heart can be used as a weapon), she begin to fear the unicorn. And when the day actually came and Sombra suggested they should really use the power of the Heart, the queen told him to leave the empire and never come back, as she said: ‘Crystal Heart is for protecting life. If you can’t understand, you have no rights to stay”. Sombra feeling betrayed, uses a dark crown’s powers, which he find trough his studies, to destroy the queen. The rest is history.