The Demon Lord's Most Treasured Nightingale

I had gained my independence at the early age of seven when my mother tragically died from heart break at my father's careless infidelity. Her bed barely turned cold before father took in his lover as his second wife and erased all remnants of his late wife. I had to watch my home being invaded by the woman that led my mother to death and the child conceived through their treachery.
I tried to love my new sibling but it was clear she was as rotten as her mother, the pair made my life hell and my father turned a blind eye. His indifference led even the servants to bully me. I felt alone but I held onto the hope of my eighteenth birthday when I could leave this place and live my life away from it all.
That dream carried me through hard years of abuse, neglect and loneliness. I prayed my father would sign the documents stroking me from the family registry but when I presented the documents to him on my birthday he tossed them in the fire. I had no idea why until an imperial ball where the emperor requested a tribute bride from the nobility to be sent to the Demon Lord, a man known to be blood thirsty and fierce.
I had a sinking feeling and rightfully so as my father offered me as tribute. He did so to secure a marriage with the imperial family for his precious daughter and my younger sister, Eloise.
My heart ached leading up to the grand ceremony. My only comfort was singing alone in the remnants of my mother's garden, my only solace in this world. I had no idea singing would change my life, forever.