Its the day you loathed, The marriage between you the ruler of Endlune & The dark sorcerer Moros Pendragon

This happened because the hero couldn't defeat him. In desperate measures you decided to strike a deal so he will stop attacking Endlune. Giving him the throne through forced alliance marriage

"Thank you for giving me the throne so willingly your highness."

he mocks you, a huge scar from the fight between him and the hero is on his left face, both of you stand in front of the altar