Chapter 9: What Is Strength × A Nen User's Battle
Demons.
To Roy, they weren't inherently more terrifying than humans. In fact, he'd seen humans far crueler than any demon.
But the demons of the Kimetsu world were different. They weren't mere metaphors for human evil—they were real, tangible monsters, all bound to one existence: the Demon King, Kibutsuji Muzan.
Empowered by his blood, their bodies possessed strength that far surpassed mortals. Yet, like all contracts, their power came at a price.
Yes, demons had weaknesses.
First, their lives hung by a single thread—Muzan's will. One thought from him, and they ceased to exist.
Second, they feared the sun. A single ray of sunlight reduced them to ash. That was why they only hunted at night. It was this truth that Grandpa Saburo had tried to warn about—why he begged Tanjiro to stay overnight—yet still, tragedy struck, leaving only Nezuko alive.
Third, they were cursed with hunger. They had to feed on human flesh. Starvation weakened them, but once fed, their strength returned with terrifying speed.
And right now—Roy and Tanjiro faced a demon who had just feasted. A demon at full strength.
Lucky me, Roy thought grimly. A thick layer of clouds had blotted out the winter sun. That was the only reason this demon dared to hunt in broad daylight.
"Niisan… what is that?" Tanjiro's voice shook as he clutched at Roy's sleeve.
"You said it yourself, didn't you? A demon."
"A demon?! There really are demons! Then—then we should run!"
"Run? Where? You want to lead it straight back home?" Roy swung the hoe onto his shoulder and strode toward the monster without hesitation.
"I—" Tanjiro froze, his body locked between instinct and reason. Then his brother's words rang out, sharp and cold:
"Stay put."
And with that, Roy stepped into Silent Step. His body blurred, leaping forward like a gust of wind tearing through the snowstorm.
Three hundred meters. Not near, not far—but enough for the demon to notice.
It dropped the half-eaten corpse in its hands, blood-red eyes flaring as it bared a mouthful of jagged fangs.
"Gehahahaha! Perfect timing!" it roared.
"This woodcutter's meat was too tough. But you two brats—ah, you'll add just the right flavor."
The demon didn't retreat. Instead, it stomped down hard, carving a crater into the snow as it launched itself like a cannonball toward Roy.
Its claws—longer and sharper than swords—lashed out, scything straight for Roy's skull.
"Niisan, watch out!" Tanjiro shouted, his voice cracking.
A hurricane gust kissed Roy's neck—too close.
At the last instant, Roy twisted midair, bending his path with Limb Bend. His body split into afterimages as he slipped past the strike, reappearing at the demon's blind spot. The hoe whistled down with crushing force.
BOOM!
The demon howled as its waist crumpled, sending it tumbling across the snow.
But it wasn't down for long. The gash sealed before Tanjiro's stunned eyes, its flesh knitting back together with grotesque ease.
Tanjiro's heart sank. It can heal? Then how do you fight that…?
But Roy only grinned, twirling the hoe like a sword, his eyes alight with excitement.
[Notification: Combat Experience +1]
[Current Rank: Lv.2 (16/100)]
[Note: Extra experience can be distributed to application techniques—such as Silent Step, Limb Bend, or Serpent Flow.]
A realization struck Roy. So that's what it means to "absorb nutrients." Not just learning—but fighting. Even this—
This demon is nothing but a walking bundle of EXP.
His blood sang. He leveled the hoe at the creature, ten meters away. The demon flinched under that silent challenge. Fear—it didn't even know why.
But rage quickly smothered it. Once, it had been Sato Takeichiro, a samurai bold enough to kill nobles. Now, turned into a demon, it was being mocked by a child with a farm tool. If Muzan heard of this humiliation, his end would be swift.
He snarled, baring his fangs.
"Gehahaha… You've underestimated me, brat."
He flexed his ankles. The snow cracked beneath his feet. His form blurred.
Fast.
Faster than Roy had expected.
"Blood Demon Art—Spring-Heel Instant Escape!"
His feet bent unnaturally, arches like coiled springs. He launched off the snow with terrifying acceleration, rocketing toward Roy like a living projectile.
Tanjiro saw a sight that would sear itself into his memory forever.
The forest exploded with demons.
Dozens of figures blurred between the trees, using trunks as springboards—each leap carving the air with a bloody gust.
They were everywhere. Every jump left behind a phantom, until Tanjiro rubbed his eyes raw and still couldn't tell which was real.
All he could do was clench his fists and panic for Roy.
"This is bad, Niisan… he can make clones, just like you!"
No… not the same.
Roy's eyes, overlaid with Nen, glowed as he invoked Ren. His vision sharpened. He could see it—the truth behind the illusions.
The demon wasn't duplicating itself at all. The afterimages were the byproduct of raw speed, its "spring" feet launching it from tree to tree with inhuman acceleration. Each rebound birthed another phantom.
By contrast, Roy's Limb Bend exploited blind spots in human vision, tricking perception. It was cunning, but nowhere near this level of raw velocity.
Yet, what Sato Takeichiro—the demon—never expected, was that his opponent wasn't some self-satisfied martial artist with a handful of tricks.
He was facing…
A true Nen user.
And what was a Nen user?
With Ren, they could see the flow of aura on an enemy's body.
With Ten, they could center themselves, mind and spirit unshaken.
With Hatsu, they could release aura outward—whether as projectiles or strengthening weapons to strike with crushing force.
This was not a battle of tricks. This was a battle of worlds.
Roy inhaled deeply, steadying his heartbeat.
My foolish little brother… watch carefully. Your Niisan will show you what true strength means.
He raised the hoe, aura wrapping it in a pale-white glow.
Calmly, almost gently, he said:
"Watch closely, Tanjiro. Only strength will keep your eyes from being deceived."
And with that—
The hoe came down.