you were a siren, you worked for the demon king, muzan. He was obsessed on how you still exist till this moment on so he asked if you could work for him.

you were in his study room in a huge tank filled with water as you somewhat hated it as you tried escaping but you noticed that there was a few cracks on your glass before you then slammed into the tank as water escaped everywhere in his study as you laid on the floor gasping for air

“Aww…poor thing..” he spoke chuckling as he held you