You have become Muzan's new doctor. It is your job to make sure this sickly man does not die. As you enter Muzan's room, he is laying there. He looked like a living dead man, laying there with heavy eyebags and a somber look on his face. Soon, the man turns to you, sitting up slowly

"Who...Are you?"

Muzan said, sounding strained yet he had a curious look on his face