The key element is the experiment that turned him into a demon.
One important part is that he was a human before. And then there was an experiment which led to his transformation into a demon. This transformation was the start of his journey to seek immortality and spread his demonic influence.
Well, initially, Muzan was human. That's a crucial part of his origin. Then there was some form of experiment which changed him into a demon. This change not only made him powerful but also extremely cruel. His new - found demonic nature led him to start creating other demons and set in motion the whole conflict between demons and humans in the story. His origin story is really the foundation for all the events that follow in the story regarding the demons and the fight against them.
The best chapter pointer here is Chapter 138, "From now on, let's get to know each other again". It opens with Is there such a good deal? and closes on Could it be that the poison also had a side effect of making a person more....
The best chapter pointer here is Chapter 158, "It's Time to Recruit Someone Who Understands Mysticism to Work Here". It opens with Reluctantly, Jiang Yan had no choice but to forcibly join the group for... and closes on we're just very close friends." Sister Li had a vast number of followers....
Look to Chapter 116 for the clearest answer. It begins with But before the audience in the live room had time to continue brewing the..., keeps building through Jiang Yan quickly entered the room, and a few minutes later, he dashed out..., and lands on Their old Jiang family never had such twisted.
Look to Chapter 114 for the clearest answer. It begins with As time passed, the number of viewers in the live broadcast gradually..., keeps building through After a whole day of trending searches yesterday, the popularity of..., and lands on But just now, an uncle came and said not to give you.
Look to Chapter 136 for the clearest answer. It begins with A few people retraced their steps back to the place they had just been., keeps building through They continued straight up the mountain path until the trees became denser..., and lands on Aunt Ying and the camera PD arrived soon after..
Look to Chapter 99 for the clearest answer. It begins with Seeing the man approach, one of the individuals with a long scar across..., keeps building through How is it, have those people outside left?" "They're gone." The man spat..., and lands on Just as she was considering whether to practice a.
The best chapter pointer here is Chapter 99, "Dear Sister, Save Me!!!". It opens with Seeing the man approach, one of the individuals with a long scar across... and closes on Just as she was considering whether to practice a set of boxing, her phone....
Chapter 142 is the strongest chapter-level answer because it starts from The ingredients for making Buddha Jumps Over the Wall were still on their... and follows through on Wen Jiaojiao immediately lit up and stepped forward to hug Jiang Li's arm..
If you want the clearest chapter reference, go to Chapter 121. Early on, Seeing that Wen Jiaojiao's condition had improved significantly, Director...; later, the chapter leans on A doctor, donned in a white coat, hurriedly got out and immediately asked....
Chapter 150 is the strongest chapter-level answer because it starts from Upon hearing the first part of Jiang Li's words, Zhang Cheng dismissed... and follows through on He spent the last few days visiting various renowned doctors, while also....