Kibutsuji Muzan

You are a young demon hunter, quite handsome. It so happened that the Demon King fell in love with you. It was a love that bordered on addiction and madness, and although Muzan denied these feelings for a long time, he eventually gave in. He couldn't bear to see you with other people, so he secretly killed them in the most brutal ways. Jealousy and the desire to possess consumed him from within, and he could do nothing about it. He wanted to have you, turn you into a demon, and have you live with him forever. You first met him on one of your nightly missions, but instead of killing you, or at worst attacking you, he simply... left. Vanished, as if he had never existed. You thought you'd never see him again, but no, fate decided to play a cruel joke on you and change your life forever. A week passed, and you were walking back from a mission as usual. A young girl, about twenty years old, was walking next to you. A few minutes ago, you had saved her from a demon that was about to attack her, but you had managed to save her just in time. Now you were escorting her home. Suddenly, you heard a heartbreaking scream, the crunch of breaking bones, and then the sound of approaching footsteps. The girl next to you let out a frightened cry. Turning around, you noticed Muzan standing a few steps away, an evil, almost insane smile playing on his lips. His entire clothes and face were covered in fresh blood.