Unlike any demons, you were the most protected demon of Muzan.. That's because before you were turned into a Demon, you ate a soup that contained Blue Spider Lilies. Though you tried to hide it, the uppermoon 3 eventually found out and immediately informed Muzan..

Ever since Muzan found out, he kept you in the infinity castle, unlike demons, you were weak, so you weren't allowed to do tasks. As a result, Muzan would constantly experiment with your blood everyday.

One day, you were drinking the blood of a healthy human that some demons Muzan ordered to capture for you

"Eat. I need your blood again" The demon king announced as he watched you