‘Demon Slayer’: Who Is the Doctor that Turned Muzan into a Demon?

Muzan Kibutsuji is the main antagonist of Demon Slayer. And while he has done numerous horrible deeds during his lifetime, Muzan is not important simply because he is a ruthless, narcissistic murderer, but also because he has a great story behind him, and in this article, we are going to talk about that story. We have already explained how Muzan became a Demon, and while we will go back to that story, we will also tell you a bit about the doctor that actually turned Muzan into a Demon. The doctor is enigmatic, but that hasn’t stopped us before, so we will bring you everything we know about him in this article.

The doctor who turned Muzan is an unnamed supporting character in Demon Slayer, who lived during the Heian era. He cared for the human Muzan because he was severely ill and was told he would die when he turned 20. The generous and kind-looking doctor devised a potential cure in the form of a concoction made from the extremely rare blue spider lily and administered it to Muzan. As Muzan woke up, believing that the medicine had not done its job, he killed the doctor and later realized that the medicine had indeed worked. But, he felt no remorse, as he became a Demon at that point.

The rest of this article will focus on the doctor who turned Muzan into a demon and his fate in the Demon Slayer: Kimetsu no Yaiba series. The Doctor was one of the most important characters in the Demon Slayer lore, despite being shown only once, and it only makes sense that the fans want to know what happened to this kid, so we have decided to compose this article. This article will contain some spoilers from the Demon Slayer: Kimetsu no Yaiba manga, so be careful how you approach it.

The doctor saved Muzan’s life, but he also turned him into the most dangerous and menacing person in the whole world

Now, the story we will talk about today will take us back to the Heian era of Japanese history. Now, since not all of our readers know all these details about Japanese history, we will go over the basic information so you know what time we are talking about, as these periods are quite important for the story we are about to tell you soon.

The Heian period is one of the 14 traditional subdivisions of Japanese history. This period, preceded by the Nara period, began in 794 and ended in 1185 with the Kamakura period. The old capital, Nara (Kansai), was abandoned to create Heian-kyō, the future Kyoto (Kansai). The Heian period (meaning “peace” in Japanese) is considered the height of the Japanese imperial court and is celebrated as the golden age of Japanese culture and art, including poetry. Japanese, Japanese literature and painting in the Japanese style, Yamato-e.

So, the Heian period began during the late 8th century and ended near the end of the 12th century, which is a solid time period. But why is that important? Well, the present timeline of the story takes place in the Taisho era. The Taishō era is the era of Japan that covers the period from July 30, 1912, to December 25, 1926, corresponding to Emperor Taishō’s reign.

The emperor’s failing health resulted in the shift of political power from the old oligarchic group of elderly politicians (or genrō) to the Diet of Japan and the democratic parties. This era is thus considered the period of the liberal movement known as “Taishō democracy” in Japan. It is customary to distinguish it from the previous Meiji era and the early militaristic part of the Shōwa era that succeeded it.

As you can see, there is practically a whole millennium between the Heian and Taisho eras, which is important for understanding Muzan’s position in the story; this means that the guy has been causing problems for roughly 1,000 years and that his story began a very long time ago. Now, back to the story itself.

Muzan Kibutsuji was born sometime during the Heian era, but ironically, the most powerful being in the present was exceptionally frail during his childhood. While he was in his mother’s womb, his heart stopped more than once, and he was even deemed stillborn; it wasn’t until a few moments before being cremated that he actually started crying, showing all of them that he was alive.

Now, that is where the historical part kicks in – at the time, medicine was not an exact science, and many treatments were more anecdotal than anything else. This is why the physicians at the time couldn’t really provide Muzan with the proper treatment, and we don’t actually know the nature of his illness.

Be that as it may, Muzan managed to survive, but constant medical problems scarred his life. He was practically sick, and the constant issues resulted in him developing thanatophobia and the fear of dying. He was willing to do anything to avoid death, but at that moment – another piece of horrible news arrived: he was diagnosed with an unknown disease that would kill him before he reached the age of 20. You can imagine what a shock that was for him.

At the time, though, he was under the constant care of a doctor, who watched over Muzan. We don’t know much about Muzan’s doctor, but he seemed to be a gentle person and quite knowledgeable. He also seemed to be quite experienced, as he was quite old, and he was able to help Muzan as best as he could. He was also openly described as being quite generous.

Now, you have to go back to the historical part again. It was the Heian period, and however knowledgeable the doctor might have been, there was little he could do using his medical expertise, as the science of the time simply wasn’t enough to help Muzan.

But, the doctor, being experienced and obviously quite skilled, came up with an experimental cure made out of the extremely rare blue spider lily, hoping that it could heal Muzan, but he wasn’t aware of the consequences. He administered it to Muzan, but after a while, Muzan was still feeling weak, and he thought that the medicine did not work, which meant that he would be dying soon. Furious, he grabbed a knife and killed the poor doctor, and it was only then did he realize that the cure worked, as he felt a lot stronger than before. At this moment, Muzan was turned into a Demon, and he did not regret killing the doctor.

It was only when he realized that he was vulnerable to sunlight that he regretted killing the doctor before completing his treatment, as he, himself, wasn’t able to find the blue spider lily to replicate the cure. And that is the story of Muzan’s poor doctor, who helped him, only to die exactly because he helped Muzan.