Sano had always considered himself lucky.
Back when he was human, his massive build made him the village bully. He ruled the streets, taking whatever he wanted, whenever he wanted.
That changed the day he picked a fight with the wrong person. He figured he was dead for sure.
Instead, he hit the jackpot. Muzan himself took notice, gave him his blood, and turned him into an immortal demon.
Sure, he couldn't walk in sunlight and had to eat people, but compared to the endless lifespan and insane healing? Those were nothing.
And today, his luck hit another all-time high.
The second he laid eyes on the man standing in the street, his mouth started watering.
This had to be the "rare blood" the other demons whispered about—the kind that could turn one meal into the power of hundreds, maybe thousands.
If he ate this guy, he'd shoot straight into the Twelve Kizuki. At least a high-ranking Lower Moon. Hell, maybe even Upper Moon wasn't out of reach.
The only thing that surprised him was that the man had actually noticed him watching.
Didn't matter. The guy was alone, no weapons, nothing. Bare hands against a demon? Please.
"Heh heh heh…"
Sano stepped out of the shadows with a twisted grin, voice rasping like gravel. "Kid, blame your own rotten luck for running into me."
"Don't worry, Lord Sano will make sure every last scrap of your flesh gets eaten. Not a single drop wasted."
He lunged, massive hand swinging toward Shuya's head like a wrecking ball.
Then a black blur slammed into his face.
Sano dropped to his knees, completely lost.
Who am I? Where am I? What the hell just happened?
He had no idea how he'd ended up on the ground.
"Charging at a Nen user without even checking the power gap?" Shuya shook his head, staring down at the demon he'd just floored with one punch. "Trash really is trash."
If it had been Muzan Kibutsuji standing here, the Demon King would've taken one look at a rare-blood prize like Shuya and immediately asked himself: Is this for real? Something's off.
Then he would've sent other demons to test the waters while staying hidden in the back.
"Useless. Do you even have a Blood Demon Art?" Shuya planted a foot on the demon's chest and demanded.
To him, the most valuable thing in this world wasn't the Demon Slayer Corps' breathing techniques. It was the Blood Demon Arts that Muzan's blood created.
If his original Equivalent Exchange ability could trade for one of those arts, then Muzan's blood would be an endless gold mine.
"H-how do you know about Blood Demon Arts?!" Sano's pupils shrank in shock.
The crushing pain in his chest made it hard to breathe.
"Didn't Muzan ever tell you there's an organization called the Demon Slayer Corps that hunts worthless demons like you?" Shuya said coldly. "Now answer the question. Do you have a Blood Demon Art or not?"
"D-don't kill me!"
Sano was panicking. This guy even knew about Muzan?
That explained everything. Demons were insanely strong, yet humans still ruled the surface world instead of being kept like cattle. The Demon Slayer Corps had to be the reason.
He guessed this man was probably one of them.
"Please!" Sano begged. "I was only turned a few days ago! I don't have a Blood Demon Art yet! I haven't even eaten anyone! Spare me!"
"Cut the crap," Shuya scoffed. "Who cares if you've eaten people?"
The guy wasn't one of his. Dead or alive made zero difference to him.
What mattered was that this demon had no Blood Demon Art, so his value for testing Equivalent Exchange had just plummeted.
"Huh…?"
Sano froze. He couldn't believe the man didn't care about the human-eating part.
But the cold look in Shuya's eyes was unmistakable. The demon had no doubt the guy would kill him in the next second.
All he could do was keep begging. "Please don't kill me! I swear I'm still a good person! I haven't eaten anyone!"
Good person?
Shuya almost laughed. Since when did good people jump strangers in dark alleys?
Still, the demon had some use left.
"Don't worry," Shuya said flatly, voice completely emotionless except for the slightest emphasis on the next words. "I'm not going to kill you. In fact, I'm going to give you something nice—just like Muzan did."
He conjured a silver needle between his fingers.
This wasn't an ordinary needle.
It was the Transmutation ability he and Yuriko had developed together over the past year using the zombie virus: Undead Prelude.
One prick to the brain and any normal human would instantly turn into a controllable zombie under his command.
But what about demons?
Could it turn them into obedient demon-zombies?
And if he ever got his hands on Muzan's blood… could he fuse that power into Undead Prelude and create controllable demons who kept their Blood Demon Arts?
He was dying to find out.
With a flick of his finger, the silver needle shot forward like a silver thread and buried itself in the demon's skull.
Sano's reaction was immediate.
Thick black aura erupted from his body.
"Power… so much power flooding into me!"
Sano clenched his fists in the air, eyes wild, looking every bit like a villain about to go full dark-side.
"Effect's that good?" Shuya raised an eyebrow. "Can't be the zombie toxin alone… Nen? Or both?"
At the same time, in a distant location—
A well-dressed man with wavy black hair elegantly wiped blood from his hands with a white handkerchief.
His expression stayed calm, but he murmured, "One of my demons is still alive… yet I've lost control of him?"
"Is it you?"
Muzan Kibutsuji looked up, staring in a certain direction as if gazing straight at someone.
"I didn't expect you to be capable of this already. Looks like I really need to deal with you personally."
He glanced down at the newly turned demon kneeling respectfully in front of him.
"Tamayo…?"
Then he waved his hand dismissively, voice icy. "Get out."