Chapter 18
"First time trying Sun Breathing, and it feels pretty good."
Kiriya flicked his long sword, shaking the beads of blood from the blade, and casually made that remark.
Then he heard a trembling female voice beside him.
"S-So strong..."
Kiriya paused, then turned his head to look.
The female demon’s eyes were staring straight at him.
In her yellow pupils, there was shock, relief, and even a trace of worry.
He was stunned.
This was the first time he had ever seen such a complicated expression on a demon’s face.
Especially when this one had just had her head cut off by him. Why did she look more relieved than afraid?
Oh, right.
This woman had been abused from both sides by her so-called husband and child.
She was probably beyond tired of it, so her calmness toward death suddenly made sense.
"Finally... it’s all over," the female demon whispered, then warned him, "Be careful. That one is... one of the Twelve Kizuki."
She thought that after Kiriya heard her son’s title, he would be shaken.
Even if he turned pale in fear, that would not have been strange.
After all, they were talking about the Twelve Kizuki.
But what did she see instead?
"Got it. Thanks for the warning."
Kiriya’s expression remained calm, so relaxed that he might as well have heard, ’We’re having rice for lunch today.’
"Don’t let your guard down..."
Half of the female demon’s head had already faded away, but she was still trying to persuade Kiriya.
But just then, a familiar voice rang out, making her feel as though she had been dropped into an ice pit.
"You’re about to die, and you still want to leak information about your own son to the enemy. What a wonderful mother you are."
"Rui?"
Almost by reflex, her heart clenched hard.
Before she could react any further, a huge foot stomped down, crushing the remaining half of her head into pieces.
The one who did it was a hulking demon. He stood nearly one meter ninety, with a mouth full of sharp fangs.
His face had no normal features, only round decorations like glass marbles, making him look disturbingly humanoid.
If he walked down a street, he would probably scare children half to death.
"Demon Slayer, you dare barge into my home and hurt my precious family. Have you decided how you want to die?"
The one who spoke was a small, thin boy with loose white hair.
The characters for "Lower Five" were carved into his left eye.
One of the Twelve Kizuki.
Lower Rank Five, Rui.
In terms of size, he was far smaller than the huge demon beside him, but the aura he gave off was much fiercer and far more terrifying.
Especially when those emotionless eyes fixed on someone, ordinary Demon Slayer Corps members would probably lose all courage on the spot.
But who was Kiriya?
Ever since school, he had never been ordinary!
Kiriya did not attack.
He simply stood there, quietly watching this touching display of "motherly love and filial piety," along with some truly radioactive marital harmony.
A faint mocking smile appeared on his face.
"So this is what you call family? What an eye-opening sight."
Kiriya raised the Nichirin sword in his hand.
"Since you care so much about your mother, I’ll send you down to reunite with her."
"With just you?" Rui smiled contemptuously. "You killed one useless weakling, and now you think you’re something special?"
Then, without even turning his head, he gave the order.
"Kill him."
"Don’t come near my family!"
The moment his words fell, the hulking, fang-mouthed humanoid demon let out a roar.
His thick legs stomped against the ground, and his entire body shot forward like an arrow released from a bowstring.
"Boom—"
A fist as large as a sandbag came crashing forward with terrifying momentum, making even the air tremble.
Yet faced with such a frightening attack, Kiriya stood there blankly, as though he had been scared stupid, and simply took the demon’s brutal punch straight to the face.
"Hmph. Pathetic," Rui sneered.
But in the next instant, his expression stiffened, and his whole face darkened.
"Boom—"
The hulking demon’s fist passed straight through Kiriya’s body and smashed into the ground, leaving a hole behind.
The Kiriya standing there vanished like a bubble under sunlight.
"Sun Breathing: Fake Rainbow."
"An illusion? No, an afterimage."
Rui’s eyes widened.
He searched carefully for Kiriya’s whereabouts and shouted a warning.
"He’s behind you!"
The hulking demon whipped around and threw a brutal right hook.
Unfortunately, Kiriya’s blade was faster.
"Sun Breathing: Setting Sun Transformation."
"Hiss—"
Kiriya’s Nichirin sword glowed with an orange-red light like the sun, slicing through the demon’s arm and neck as easily as a hot knife through butter.
In the blink of an eye, the battle was reversed.
"You actually sent your own father out to die first. What a good, filial son you are."
Kiriya shook the blood droplets from his Nichirin sword and smiled at Lower Rank Five.
"Idiot. Do you think you’ve already won?" Rui’s face darkened, but his posture remained composed.
"I’m not on the same level as those pieces of trash."
Kiriya’s strength had exceeded his expectations, but only slightly.
Next, he would make Kiriya experience the terror of the Twelve Kizuki firsthand.
With that thought, a dense web of spider threads appeared between Rui’s hands.
"Uh..." Kiriya looked surprised, then nodded. "I have to admit, your cat’s cradle skills really are on a whole different level compared to theirs. You practiced hard, didn’t you, kid?"
"All you know how to do is run your mouth."
Rui’s hands instantly turned crimson as the power of demon blood activated.
"Blood Demon Art: Murderous Eye Basket."
In the blink of an eye, the spiderweb that looked like a cat’s cradle rapidly expanded, surrounding Kiriya like a cage and leaving not a single gap for escape.
"Get sliced into mincemeat by my threads!"
Rui narrowed his eyes, already impatient to see the miserable sight of Kiriya being cut into pieces.
’This guy smells pretty good. I can enjoy him afterward.’
That thought flashed through Rui’s mind.
However, his confident expression broke almost immediately.
"Sun Breathing: Burning Bones, Summer Sun."
Kiriya spun at high speed, and the Nichirin sword in his hand created a blazing vortex like a tornado, completely cutting apart every spider thread that came near him.
As everyone knew, spider silk feared fire, so Sun Breathing was practically made for dealing with this.
"What?"
Rui was stunned by the scene.
A mere human had shattered his Blood Demon Art in a single counterattack.
That level of strength was far too absurd!
"Hey, kid, don’t space out."
Kiriya’s figure appeared beside Rui like a ghost, and the Nichirin sword in his hand swept horizontally.
"Sun Breathing: Dance."
Rui’s heart tightened.
He tried to dodge, but it was already too late!
"Hiss—"
Kiriya brushed past Rui, and the Nichirin sword in his hand easily cut across Rui’s neck, sending a head covered in white hair flying into the air.
"Nice idea."
An interested look appeared on Kiriya’s face.
"You cut your own head off with your threads ahead of time. Kid, you’ve got fast reactions."
On the other side, Rui controlled his threads, pulling his flying head back and reattaching it.
When he looked at Kiriya again, his eyes were filled with rage.
"You bastard... Again and again, you keep getting in my way! You even damaged my precious body! Unforgivable. Unforgivable."
"Oh? What are you going to do about it? Show me."
Kiriya held his Nichirin sword and took a stance.
He genuinely wanted to see the other party’s ultimate move.
After gaining Sun Breathing, Kiriya had a very strong feeling—he had become stronger. Far stronger than before.
Even though his ability values were still only around Level 1, he felt that even in a pure blade-to-blade fight against adventurers who had just entered Level 3, he would not be at any disadvantage.
This Breathing Style suited him too well. It was almost as if it had been tailor-made for him.
Kiriya even had a strange illusion for a moment.
Could he be the reincarnation of Yoriichi Tsugikuni?
Otherwise, why would it fit him so perfectly?
But after thinking about it carefully, he understood the reason.
His body had already been transformed by Hashirama’s cells and Hestia’s divine blood into something close to a Sage Body.
That kind of physique naturally contained a powerful Yang force.
That tremendous vitality and life force, combined with all of his ability values rising to S-rank, meant his body could naturally withstand the burden of Sun Breathing.
Only because of that could he bring out its true power.
The sudden surge in strength gave him an urge to let loose, so when he learned that the boys destination was Natagumo Mountain, he had rushed over eagerly.
His goal was to use this Lower Rank demon, one of the Twelve Kizuki, as a whetstone to test the true quality of his own strength.
The good news was that he had indeed become stronger, strong enough to easily suppress a Lower Rank demon among the Twelve Kizuki.
The bad news was that he had become too strong.
This Lower Rank demon put no pressure on him at all, leaving him with the awkward feeling of swinging a sledgehammer at a walnut.
"Come on, kid. Give it everything you’ve got. Don’t embarrass yourself."
Kiriya focused his mind completely, preparing to take the other party’s ultimate attack head-on.
"Blood Demon Art: Cutting Thread Rotation."
Completely enraged by Kiriya’s dismissive attitude, Rui unleashed his strongest Blood Demon Art with all his power.
In an instant, crimson light surged between Rui’s palms, and countless blood-red threads crisscrossed within it.
Then those blood-red threads suddenly expanded, rushing toward Kiriya like thousands upon thousands of venomous snakes.
The threads were as hard as the strongest steel, and their sharpness far surpassed ordinary blades.
Everything they passed through was cut cleanly in two.
Leaves, trees, rocks—before those threads, all of them were as fragile as thin paper.
"This is it. This is what I wanted!"
Faced with this attack, the intense sense of danger made Kiriya feel as though all the blood in his body was burning.
Then he moved.
The Nichirin sword in his hand emitted an orange-red glow like a halo around the sun, drawing a winding, powerful arc through the air like a swimming dragon.
"Sun Breathing: Sun Halo Dragon."
Against slashes carrying such scorching heat, even those hardened spider threads strengthened by Blood Demon Art became pathetically fragile.
In the blink of an eye, that Sun Halo Dragon grew larger and larger in Rui’s pupils.
Then it filled his entire field of vision.
"Hiss—"
Rui’s head flew into the air once more.
But this time, there was no self-decapitation to escape death.
This time, his life was cut off completely.
"You... are you human or demon?"
Rui’s head fell to the ground.
His eyes stared fixedly at Kiriya, unable to believe that he had been defeated so easily.
He was Lower Rank Five. He had the potential to rise into the Upper Ranks.
How could he lose here?
"Kid, in your next life, when you play house, don’t be such a tyrant."
Kiriya did not answer his question. He simply said that, then turned and left.
Only Rui remained behind, dead with his eyes still open.
...
"Hah... hah... hah..."
On the hillside, several slender figures were running desperately.
They were Rui’s "family," the existences known as "younger sister," "older sister," and "younger brother."
For the past few decades, perhaps even longer, they had been forcibly kept here, made to play Rui’s twisted game of house and satisfy their superior’s warped idea of family.
They suffered all sorts of abuse, both open and subtle, but at the very least, they would not be hunted down by some random Demon Slayer and have their heads cut off.
But now, Rui was dead!
The family member who had always protected them, the powerful Twelve Kizuki, Lower Rank Five, was dead!
The moment Rui died, they sensed it through the faint connection in their blood.
Then panic erupted like a volcano.
If even Rui, who was as powerful as a god to them, could be killed, what would happen to small fries like them?
Run!
They had to run!
The farther, the better.
No matter what, they had to get as far away from that monster as possible.
These creatures were all demons, and their stamina far exceeded that of ordinary people.
Soon, they passed through the vast mountain forest and were just about to leave this dangerous area.
Freedom seemed to be within reach.
"Hurry! We’ll be safe soon!" the older sister at the front shouted in delight.
The others perked up as well and quickened their pace.
But just then, several figures appeared ahead of them.
A half-naked boy wearing a boar’s head, a boy with red hair and red eyes wearing Hanafuda earrings, and a timid-looking boy with blond hair and blond eyebrows.
Naturally, they were Inosuke, Tanjiro, and Zenitsu, who had entered the mountain to search for the other Demon Slayer Corps members.
While Kiriya was fighting Rui, they had not been idle either.
They had been busy gathering the injured Demon Slayers together and had their hands full.
But then, demons suddenly barged in, and the three of them immediately grew tense.
"Ah! Demons!" Zenitsu screamed. "And why are there so many of them? So scary!"
Zenitsu’s reaction immediately made the demons relax.
"What? they’re just a few rookie Demon Slayers!"
The older sister at the front chuckled and licked her lips.
"Perfect. We can bring some food with us for the road. Capture them!"
Among them, aside from Rui and "Father," she was the strongest.
With a single order, the brothers and sisters beside her immediately moved, charging toward Tanjiro and the others.
They thought the process would be as simple as a lion hunting a rabbit, with them standing above as predators who could take whatever they wanted.
Especially after seeing the timid yellow-haired boy suddenly kick his legs out and faint, they became even more certain of it.
However...
"Water Breathing, First Form: Water Surface Slash."
"Beast Breathing, Second Fang: Slice."
Those two so-called rookies attacked without hesitation.
Their swift slashes left the two demons with no time to dodge, and their heads were cut off directly.
"Nani?"
The older sister was shocked and instinctively summoned countless threads to grab Zenitsu.
Those two were dangerous!
She needed to take a hostage, or she would die here!
Unfortunately...
"Thunder Breathing, First Form: Thunderclap and Flash."
A streak of lightning flashed before her eyes.
She felt only a sharp pain in her neck... then her consciousness sank into eternal darkness.