My name is Kibutsuji Muzan, and I am an ordinary Demon King who has lived for over a thousand years. I say ordinary because, like the common demons I created, I fear sunlight; exposure to it means death for us. My dream is to become a perfect being.
Over a thousand years ago, I was born into an ordinary noble family, but I was somewhat unusual, as I carried a strange illness from birth.
Although I had been treated by many doctors since I was old enough to understand, they were all helpless. But I wasn't panicked at all, because one day a famous doctor came to our home.
The famous doctor treated my illness with a special method, but my illness still didn't get better. I started to panic a little. I chose to kill that famous doctor. My illness wasn't cured, so why should he live?
After killing the famous doctor, I regretted it, because I discovered that my illness was cured. However, what I regretted wasn't killing that famous doctor, but rather why I didn't kill him a little later. Although my illness was cured, it wasn't completely cured.
Without undergoing the final treatment, I was no longer bothered by illness and, in a sense, gained immortality. But from then on, I feared sunlight; I felt that I would die if exposed to it. In addition, human flesh and blood made my mouth water, and I began to eat people. Although I found that I could also survive by eating beast meat, I had no such intention. Why should I settle for less when there's delicious food available?
Fearing sunlight is indeed an annoying thing; only being able to go out at night is truly tiresome. But that's okay; at least I'm still alive.
One day, I received news that the blue spider lily could make me unafraid of sunlight. I began to have an idea: to become a perfect being.
I started searching the entire world for the blue spider lily, but the power of an ordinary Demon King like me was, of course, limited. So, I began creating demons, sending them to help me find the blue spider lily. This was good, though; even after living for so many years, I still hadn't fully understood the outside world, so letting these tools bear the risks was excellent.
Many more years passed, and I still hadn't found the blue spider lily. These useless creatures, they're completely worthless, just a waste of my blood. However, after all these years, I've also discovered a few things: demons indeed grow stronger by eating humans, the more they eat, the stronger they become. And also, that I am the strongest.
However, this is not surprising. After all, I am the progenitor of demons, and also the demon who has eaten the most humans. I can no longer remember how many people I have eaten, but that is not important. Just as those useless creatures say, do you remember how many loaves of bread you have eaten?
After all these years, nothing has been able to interest me. Only the blue spider lily is my obsession; besides that, disguising myself as a human is also quite good. After I get tired of them, I'll eat them. The look of disbelief on their faces truly intoxicates me.
One day, I met a human with good potential. His name was Kokushibo, and his obsession was to surpass his younger brother. How boring! For a Demon King like me, power is no longer something to strive for, because I already stand at the pinnacle of the world.
I bestowed my blood upon him, and as a demon, he was indeed very powerful, probably second only to me. I let him follow his heart, and he went to find his younger brother. Heh heh, I suppose his younger brother will be eaten by him.
I observed his memories, anticipating him eating his own younger brother. Actually, I've seen many dramas of demons devouring their relatives, but those were all brainless creatures. This one today, however, possessed complete sanity, so he should bring me a lot of entertainment.
Heh, he actually lost to his younger brother. However, this also made me a little interested in his younger brother. It's been a long time since I've made a move. Let me see how much strength he can make me use. If he performs well, I don't mind giving him some blood too.
Soon, I met his younger brother, Yoriichi Tsugikuni. The first thing he said to me was, "What do you consider life to be?"
Ridiculous. My own life is, of course, the most precious thing. What do the lives of other humans or demons have to do with me? What a foolish human. I decided to teach him a lesson.
My few attacks were actually dodged. Not bad, he piqued my interest. Then, he drew his sword, and I felt the fear of death for the first time in a long while.
However, I was not at all panicked. I had already thought of a way to kill this man. As he approached me, I exploded my body, then scattered in all directions. He slashed many times, but it was useless; he merely destroyed most of my physical form.
I was severely wounded as a result, but I was not at all panicked. I hid for many years. I heard that Peng Zu, who planted flowers, lived for eight hundred years. That man probably couldn't live that long. I don't know when he died. Anyway, he had been dead for many years when I came out.
So, what's the point of being so powerful? Can you outlive me? After that man died, I was the strongest in the world, but I didn't develop the idea of ruling the world because of it. I just want to live well, and also find the blue spider lily and become a perfect being.
I sent people to destroy all of that man's legacy. I also confirmed it multiple times, and had others confirm it multiple times. I finally felt at ease.
Until three years ago, I received news that there was actually a direct descendant still alive. How ridiculous! This time, I will handle it myself.
Then, I saw that face. I almost split into eighteen hundred pieces again, but fortunately, I stopped myself in time. The face was indeed the same, but it wasn't that man. I breathed a sigh of relief, then became enraged. How dare you look like that to scare me! I made a move, and the moment that person opened his eyes, I almost exploded myself again. Transparent World, just like that man! Fortunately, this person had an illness, so I dealt with him and his family.
I thought everyone and everything related to that man had disappeared, until today, when I saw that man's earrings on a young demon's ears.
I didn't make a move. Although this young demon seemed to have no power, what if? Besides, what if he was a bait? Although the Demon Slayer Corps is useless, what if they got that man's legacy and ambushed me here!
I casually turned a passerby into a demon and had him hold back that young demon. When I returned home, I sent two of my subordinates to scout ahead. It doesn't matter if they die; I can create such cannon fodder at will anyway.
However, if they die, I'll just change my identity first. After all, I'm tired of this identity!