Demon Slayer: Guardian of the Forest

Taiping Saburo's face, marked with deep black patterns, glistened with a few cold beads of sweat. He had never anticipated that this frail old man before him would wield such a fierce, peculiar fighting style, nearly taking him down.

By all rights, a man of such age shouldn't possess this kind of strength. Humans were not like demons; their lifespans were finite, their bodies aged, and they weakened with time. While demons lived on eternally, constantly growing stronger, humans could never hope to keep up. Even those Demon Slayer swordsmen who had mastered the Breath techniques—despite their impressive strength—faced inevitable decline. Muscles would weaken, breaths would fade, and the passage of time would always betray them. Demons would grow stronger, while even the strongest Pillars of the Demon Slayer Corps would grow weaker as they aged.

But Saburo sensed something distinctly different about this old man. To him, the aura surrounding Old Man Morimoto seemed to intensify, as if his dried-up muscles were expanding, his breath growing stronger and more focused. He resembled a withered sponge, now swelling as it absorbed life itself.

"Something's off—this old man is different! Could it be his Breath technique? Breath of the Forest, perhaps? I've never heard of that... Could it be a new method from the Demon Slayer Corps?" Taiping Saburo's face hardened, his gaze sharpening as he analyzed the old man opposite him. Having lived nearly a century as a demon, he had witnessed countless shifts among the Lower Moons of the Twelve Kizuki.

Unlike the seemingly unchanging Upper Moons, the Lower Moons were in a state of constant turmoil. Bloodbaths and reassignments were common, and more than a few Lower Moons had perished at the hands of Demon Slayer swordsmen. In the competitive hierarchy of the Lower Moons, retaining one's position was no simple task.

Since becoming the Lower Moon Four, Saburo had always been cautious, unlike the bloodthirsty demons obsessed with power and status. He craved strength, but more than that, he valued his life. Saburo knew that to grow stronger, he needed to devour more humans, to earn more favor—and blood—from that revered master. But survival always came first.

So Saburo chose to stay hidden, avoiding the attention of the Demon Slayer Corps and growing his strength quietly and carefully. His restraint had paid off, as the Demon Slayer unit sent to hunt him now clearly didn't expect a Lower Moon to be lurking on Mt. Shiroi.

As these thoughts ran through his mind, Saburo recalled another demon—a fellow Lower Moon ranked below him. That demon, rather than craving power or engaging in slaughter, preferred to play harmless games, wasting the precious blood bestowed upon him. But strangely, their master tolerated this behavior. Saburo couldn't understand why, but he knew better than to mimic it.

Old Man Morimoto's attacks grew even more ferocious. Saburo began to feel the urge to retreat—not out of fear of losing, but simply because he saw no reason to waste his energy on this dried-up old man.

Then, suddenly, the situation shifted. Morimoto's ferocious assault halted for a split second—a momentary pause that gave Saburo the opportunity he needed.

With a swift swing, Saburo's whirling flail hurtled toward Morimoto's head. But as the weapon neared his forehead, Morimoto managed to raise his Nichirin sword in time, blocking the deadly blow.

Yet, the immense impact of the flail still sent Old Man Morimoto crashing backward, colliding against a large tree with a heavy thud.

Coughing up a mouthful of blood, Morimoto wiped the trickle from his lips and, leaning on his Nichirin sword, forced himself to stand again. He glanced down at his trembling arm—beneath his clothes, his muscles, though appearing full, were merely the effect of the Breath of the Forest. His age was beginning to take its toll.

"Old man!" Saburo sneered, baring his fangs. "I can see your weakness. I've changed my mind—you'll die here along with these other pests!" Saburo's cruel grin widened, and with a flick of his fingers, dozens of his spiked, whirling flails spiraled toward Morimoto.

"A Morimoto never backs down! I will fight to my last breath!" Morimoto's voice, though aged, resonated with unyielding determination.

"Die!"

Whoosh!

A black shadow darted into Saburo's line of vision, pouncing onto his face. A surge of pain coursed through him, disrupting his attack. The flails intended for Morimoto lost their trajectory, allowing him to dodge them with ease.

Saburo snarled in frustration as he finally pried the assailant from his face, only to find himself staring at a small, snarling Shiba Inu, its sleek coat gleaming in the moonlight.

"What in the world is this mutt?" Enraged, Saburo slammed the dog, Enji, to the ground, swinging one of his heavy flails down upon it.

But Enji, having activated his demon form, dodged with red-eyed agility, weaving around Saburo in a flash. Before the demon could react, a blue-bladed Nichirin sword thrust straight for his back.

Clang! A piercing clash of steel rang out.

A demon's hand had intercepted the Nichirin blade.

Saburo's face twisted with rage as he stared at his assailant—this one was no human. Black claws gripped the sword, red-veined eyes glinting with malice, and sharp fangs peeking from his lips. His attacker was none other than a demon: Shinichi!

Gripping the Nichirin blade with all his strength, veins bulging on his forehead, Shinichi struggled to pierce Saburo. But it was as though his sword was lodged in unyielding stone.

"You… you're a demon! How dare you wield a Nichirin blade! Just what are you trying to do?" Saburo roared, swinging his arm to hurl both Shinichi and his sword away.

Thud! Shinichi's body crashed into a tree trunk, snapping it before he tumbled to the ground.

But his demonic resilience allowed Shinichi to quickly stand again, gripping his Nichirin sword and locking eyes with Saburo.

Meanwhile, Saburo, dislodging the tenacious Enji from his body, tore the small dog apart in a swift, brutal motion before tossing the pieces away.

In the short exchange, Shinichi had caught a glimpse of the demon's golden eyes and recognized the kanji inscribed there. This burly demon before him was one of the Twelve Kizuki—the Lower Moons, the ranks that many demons dreamed of ascending to.

"So, this is a member of the Twelve Kizuki," Shinichi thought, tightening his grip on his sword. "He's strong—way beyond me in power, speed, and reflexes. I'm no match for him." Within seconds, Shinichi could assess the vast difference in their abilities.

But even so, Shinichi didn't retreat. Running from a Lower Moon would only mean the end of his ambitions—his chance to one day face and avenge himself against that demon Muzan. Besides, he knew there was no escape from an opponent like Saburo.

Thus, the two demons squared off, separated by their overwhelming difference in power.

Saburo glared at him, his golden eyes ablaze. "You dare raise a Demon Slayer's blade against a higher-ranking demon? Do you even understand what you're doing, boy?" He scoffed. "Today, I'll rid the world of you on behalf of our master! Blood Demon Art: Wheel Axis!"

Saburo raised one arm, and the ground split beneath Shinichi's feet, sending dark shadows spiraling toward his face.

"Blood Demon Art: Blood Surge!" Shinichi summoned all his strength, pushing through the fatigue weighing down his body. His blood burned through his veins, his muscles pulsing, his skin heating as he tapped into his full demonic power.

Boom! Amid the swirling dust and smoke, Shinichi narrowly evaded Saburo's onslaught. As the dust settled, he saw the enormous stone disks, each the size of a millstone, embedded in the ground and slowly rotating.

Failing to strike Shinichi, Saburo's patience finally snapped. The wooden gears around him creaked, their surface fracturing before they shattered completely. As they broke apart, the earth quivered beneath his feet.

Rustle! Rustle! Rustle! Thin, whip-like ropes burst from the ground, snaking toward Saburo and quickly entwining his limbs and joints. In seconds, they wrapped his body in a full armor-like bind of woven rope.

"Blood Demon Art: Rope Armor!" A wave of energy pulsed outward from Saburo, distorting the air around him.

His heart pounding, Shinichi felt his grip on his sword trembling under the intense pressure. He knew it wasn't fear—it was the instinctual subservience ingrained in his demonic blood toward a higher-ranking demon.

Whoosh! This time, Shinichi acted first, abandoning any attempt at finesse. He had no skillful techniques to rely on; the Nichirin sword was his weapon solely because it could harm and kill demons. And so, his attack was straightforward—a powerful downward slash aimed at Saburo.