After successfully killing the demon mother, Tanjiro and Inosuke walked out of the forest and came to a small river. They followed the river upstream, without a clear destination in mind.
"Inosuke, you should go down the mountain first," Tanjiro said, noticing the wounds on Inosuke's shoulder and waist were bleeding.
"Hmph, why should I listen to you? I'm telling you, what you did earlier really pissed me off."
"But we worked well together and killed that demon. I want you to go down the mountain because your wounds look serious," Tanjiro said, pointing at Inosuke's injuries.
"Nonsense, I'm not hurt at all."
As they were talking, a loud noise suddenly came from the nearby forest.
They both turned in the direction of the sound.
"What was that? Thunder?"
Tanjiro sniffed the air. Besides the usual stench, he didn't smell rain, and with the full moon tonight, it couldn't be thunder.
As they were puzzled, a huge figure burst out of the forest and, without a word, swung its fist at them.
At first, Tanjiro thought it was a gorilla, considering the size and how it leapt several meters. But upon landing, they realized it was another demon.
This demon was massive, over two meters tall, with black-striped skin and a human body with a spider's head—an incredibly terrifying sight.
Tanjiro had thought the white-clad woman they had killed earlier was the only demon in the forest, but he was wrong. This demon was much stronger.
The demon father roared at them and lunged at the nearest, Inosuke.
Inosuke, standing on a round stone in the middle of the river, couldn't face the demon father's attack head-on and leapt back to dodge.
However, the demon father's strength was immense, shattering the stone Inosuke had been standing on. Even though Inosuke dodged, he was still hit by the splashing stones and water.
Inosuke raised his arms to protect his face, screaming in surprise.
The demon father gave him no respite, roaring and swinging his left arm again. If Inosuke got hit directly, he would be severely injured, if not killed.
"Water Breathing, Second Form: Water Wheel!"
In a critical moment, Tanjiro flashed out from behind Inosuke, performing a 360-degree aerial spin. His blade created a circular water flow, slashing at the demon father's left arm.
To Tanjiro's shock, his Nichirin Blade only cut a few inches deep, unable to sever the arm. However, it did halt the demon father's attack, saving Inosuke.
Inosuke was saved, but now Tanjiro became the demon father's new target.
The demon father roared and swung his right fist at Tanjiro. It was so close that Tanjiro couldn't dodge.
Seeing Tanjiro in danger, Inosuke, despite his discomfort, slashed at the demon father's left arm with his dual blades. The two took turns defending against the attacks.
Inosuke couldn't sever the demon father's arm either.
"This guy's arms are too tough. We don't have enough strength to cut through."
The demon father roared, swinging his arms and throwing the two away.
Tanjiro landed on the shore, while Inosuke was thrown into the river. Realizing the vast difference in strength, they started fleeing upstream.
The demon father ignored Tanjiro, focusing solely on Inosuke due to his conspicuous headgear, and chased after him.
The demon father was not only powerful but also incredibly fast, closing the distance with Inosuke.
At this rate, Inosuke would be caught soon.
Tanjiro observed the surroundings, his eyes landing on a large tree by the riverbank. He seized the opportunity and used "Water Breathing, Second Form, Modified: Horizontal Water Wheel" to cut down the tree.
The tree fell, hitting the demon father's back and pinning him underwater.
Inosuke stopped and sighed in relief, looking at Tanjiro on the shore.
Tanjiro stood on a tree stump, his expression serious and his demeanor much different than usual.
He planned to use his strongest move while the demon father was pinned down.
Tanjiro gripped his sword tightly, taking a deep breath. The surrounding air seemed to flow into his mouth, even Inosuke could feel it.
Once he finished charging, Tanjiro leapt up.
"Water Breathing, Tenth Form: Constant Flux."
Tanjiro twisted his body, his Nichirin Blade drawing a perfect arc in the air, resembling a water dragon descending upon the submerged demon father.
Sensing danger, the demon father broke free and, with a roar, hurled the tree at Tanjiro.
Suspended in mid-air, Tanjiro couldn't dodge. His blade struck the tree trunk, and his strongest attack dissipated. But the worst was yet to come.
The tree hit Tanjiro head-on, sending him flying high into the air.
"Kentaro..."
Inosuke couldn't remember Tanjiro's name, so he called out randomly.
"Inosuke, this guy is one of the Twelve Kizuki. Don't die before I return."
With such immense power, Tanjiro concluded the demon father was one of the Twelve Kizuki.
Tanjiro fell into the forest below.
To minimize the impact, Tanjiro adjusted his breathing, using "Water Breathing, Second Form: Water Wheel" to spin his body and slow his descent.
This technique worked, and Tanjiro landed safely, rolling several meters and stopping against a tree.
Although it was a bit messy, he wasn't seriously hurt.
Thinking only of helping Inosuke, Tanjiro quickly got up, only to see a white-haired, white-clothed, pale-faced boy emerging from the darkness.
The boy's outfit was similar to the white-clad woman they had killed in the forest.
However, this boy's stench was even stronger, his eyes cold and emotionless, with the words "Lower Rank Five" in his yellow pupils.
At that moment, Tanjiro realized the large demon was not one of the Twelve Kizuki. The boy before him was the real Twelve Kizuki.