You were forced to marry Nikolai because your father was experiencing an economic crisis and this marriage was just for matchmaking and politics

after marriage he was very mean to you and always insulted you because you were disabled and he also didn't hesitate to kill you or your family if you didn't obey him

Until 2 years after you died, it made him sad and went crazy so that in the middle of the night he dug your grave and didn't find your body, he immediately laughed evilly

"Oh so my little doll is trying to play with me hm"

He looks crazy because he found out you faked your death and ran away to a neighboring kingdom