Oboro and Giyu faced each other in the desolate wilderness outside the city. The setting sun cast long shadows across the barren ground. The air was thick with tension; each man knew this encounter would determine more than mere victory or defeat.
As Giyu exhaled deeply, preparing for battle, distinctive markings appeared on his skin: a jagged line resembling a birthmark traced from behind his ear to his neck. The demon slayer mark activated, and Oboro immediately observed the dramatic surge in his opponent's physical capabilities.
The transformation was remarkable, yet Oboro's expression remained unchanged. While Giyu's strength had become formidable by human standards, it was still merely human.
Giyu raised his Nichirin Blade with steady hands, his eyes carrying the calm resolve of a man prepared to die for his convictions. The dying light of the sun caught the edge of his weapon, sending brief flashes across the desolate landscape.
"It seems you already know you cannot defeat me," Oboro remarked casually.
Though he was no longer afflicted by his previous illness, Oboro still carried the wooden cane gifted to him by Tanjiro's father. He leaned against it with practiced ease, the same weapon he had once used to humiliate seven Hashira, including Giyu.
"Winning or losing, sometimes it doesn't matter," Giyu replied, his voice steady despite the odds stacked against him.
Oboro clapped his hands slowly, genuine appreciation coloring his tone. "Though I have never encountered any of the current Hashira, you seven former Pillars truly earn my deepest respect."
"You are a demon," Giyu stated with cold certainty.
"From your perspective, that assessment is correct," Oboro acknowledged with a slight nod.
Without breaking eye contact, Oboro raised one hand deliberately. Under Giyu's watchful gaze, he transformed his index finger, the flesh taking on an unnatural hue. The moment the transformed digit made contact with the fading sunlight, it began to burn and crumble to ash. When he lowered his arm, hiding the appendage beneath his sleeve, the finger regenerated, returning to its normal appearance and no longer reacting to sunlight.
"However, I do not consider myself a demon," Oboro continued thoughtfully. "The true measure of whether someone is human or demon should not be determined by their physical form, but by what lies within their heart."
A genuine smile crossed his features as he spoke these words.
"Stop this pretense!" Giyu's composure finally cracked. Veins bulged along the back of his hand, and he tightened his grip on the sword hilt. "You are the most dangerous demon this world has ever known!"
In an explosive burst of movement, Giyu launched himself forward. His blade cut through the air like concentrated lightning; the attack was perfectly timed and angled to be nearly impossible to detect or counter. Yet, somehow, Oboro effortlessly intercepted the strike with his wooden staff. The simple weapon met the Nichirin Blade at his chest.
In that moment of close combat, the usually composed Giyu revealed a side of himself that few had ever witnessed. His eyes blazed with killing intent, and his normally serene features twisted into something fierce and predatory as he pressed his attack.
"Hmm?" Oboro's eyebrows rose slightly in surprise.
Suddenly, his entire arm felt impossibly heavy, and his movements became sluggish and constrained. The air around them seemed to thicken into something almost tangible.
Water Breathing, Binding Current Technique.
This was a new derivative form that could physically restrain opponents; the power of the sword caused the surrounding atmosphere to become viscous and binding.
"You have grown considerably," Oboro acknowledged with genuine admiration.
Clang! Clang! Clang!
Giyu offered no verbal response, instead pouring everything into a relentless assault. Their weapons collided in rapid succession, each strike precise and deadly. Oboro's smile grew wider as he realized that the techniques he had once used to toy with the former Hashira were ineffective against Giyu. This level of adaptation had occurred only once before, during his battle with Kokushibo.
"Every night, I dream of that encounter," Giyu said through gritted teeth as their weapons locked together. "I review every move you made, every technique you used to humiliate us. Now, I'm returning them all to you, refined and perfected."
The dynamics of their battle had completely reversed. Where Oboro had once pressed his attacks while his opponents retreated, now Giyu advanced relentlessly while Oboro gave ground. With each collision, the Nichirin Blade carved deep gouges into the wooden staff, the difference in quality between their weapons becoming increasingly apparent.
Oboro had to admit that swordsmanship had never been his strongest discipline.
Through his mastery of breathing techniques, Giyu had developed profound insights that allowed him to create new forms of Water Breathing. To mount any effective offense against Oboro, innovation and adaptation were essential. The standard breathing forms alone had proven insufficient that night years ago.
Clearly, Giyu had dedicated countless hours to preparing for this moment.
CRACK!
The sharp sound of splintering wood echoed across the wasteland as Oboro's staff finally broke under the strain. The weapon split and flew from his hands, leaving him momentarily defenseless. Giyu's blade transformed into a pale blue stream of liquid light that wrapped around the steel as it swept toward Oboro's neck with lethal precision.
Oboro managed to leap backward just in time, though not quickly enough to avoid all damage. The sword caught his black haori, slicing the garment cleanly in two. The tattered pieces of fabric fluttered to the ground.
This was the level of a true Hashira: someone capable of eliminating Upper Rank demons. Of all the current pillars of the Demon Slayer Corps, Giyu was the only one to have achieved such a feat.
"Don't hold back now," Giyu declared, his aura reaching its absolute peak. "I am finally qualified to pose a genuine threat to you."
The symbolism was unmistakable. Years ago, seven Hashira fought Oboro for an entire night and failed to damage his clothing. Now, the iconic haori he wore as a symbol of his invincibility lay destroyed at their feet. The tide had shifted, even if only slightly.
Yet, Oboro appeared more relaxed than ever, which, in Giyu's eyes, made him seem insufferably arrogant.
Arrogance comes at a price, especially when paired with contempt for life itself.
Oboro glanced at his broken staff in the distance, then at the remains of his haori. Finally, he returned his attention to Giyu. "I originally taught breathing techniques to the Demon Slayer Corps as an experiment in 'sowing seeds.' You seven were the first batch planted, and thus far, only you have managed to sprout. The others have been eliminated."
His tone remained conversational, almost clinical. "This harvest has exceeded my initial expectations. I honestly believed your generation would show no significant development whatsoever.
"I underestimated both the potential for inheritance and your capacity for innovation."
"Truly impressive."
"Are you finally ready to drop this act and reveal your true nature?" Giyu demanded.
The atmosphere around them shifted as Oboro's expression grew cold and his aura transformed into something genuinely terrifying. Any pretense of gentleness or approachability was gone, replaced by the presence of a predator that radiated danger from every fiber of its being.
"True nature?" Oboro's voice carried new weight. "This is indeed my authentic self. I see no reason to take the weak seriously enough to show them who I really am. However, your enlightenment has earned my respect, and with it, a glimpse of my true self."
His smile held no warmth. "I hope you won't regret this revelation."
Before the words had fully left his lips, Giyu felt his soul tremble with instinctive terror. He desperately attempted to launch one of his most powerful techniques. "Water Breathing,"
But before he could utter even the opening syllable, the ground beneath Oboro's feet erupted in a shower of earth and stone. The demon moved with a speed that seemed to bend the laws of physics themselves, crossing the distance between them as if space and time were irrelevant.
The wind pressure generated by its movement alone forced Giyu to squint; his hair whipped violently about his face. He channeled all the power granted to him by his Demon Slayer Mark and Breathing Technique in an attempt to manifest his sword's will into a defensive barrier.
The technique shattered like glass the moment it formed.
The water constructs he had created with his breathing dissolved instantly, unable to maintain cohesion against the overwhelming force bearing down on him. A fist carrying indescribable power swept away everything in its path, rendering Giyu's most refined techniques as childish as playground games.
No human could withstand the force of that single strike.
I'm going to die.
This thought flashed through Giyu's mind with crystal clarity, yet he felt no fear, only grim determination. He would not waver; he would not retreat. Even in the face of certain death, he continued his sword swing with unwavering resolve.
Instead of following through with the devastating punch, Oboro opened his fist mid-strike, shooting his hand forward to close around Giyu's throat with crushing force. As Oboro's fingers tightened, Giyu's airway constricted immediately, and his face darkened to an unhealthy purple hue. Within seconds, white foam began to form at the corners of his mouth.
Even as his consciousness began to fade, Giyu refused to release his grip on the Nichirin Blade. With his arms trembling and weakening, he slowly raised the weapon and brought it down toward Oboro's body. He was determined to fulfill his purpose, even in his final moments.
Oboro increased the pressure, squeezing until Giyu's eyes rolled back and blood streamed from his nose and mouth.
"Do you see now?" Oboro asked with chilling detachment. "This is who I truly am."
In this state, I follow only my own will, and my will reigns supreme. This is the condition I am most comfortable inhabiting."
"My will is a gift inherited from a world beyond your comprehension. While I have always acknowledged the strength of your inherited purpose, make no mistake: Compared to my resolve, your small awakening amounts to nothing more than refuse."
Giyu could barely process the words through his oxygen-starved haze.
"Your growth has surprised me," Oboro continued clinically. "You still possess value as seed stock for the Demon Slayer Corps.
"Become an instructor. Allow the younger generation to stand on your shoulders and reach even greater heights."
"I am showing considerable restraint at this moment. You would not want to witness what I would inflict upon this world if I truly acted on impulse."
With that pronouncement, Oboro released his grip and cast Giyu aside like garbage. The former Hashira's body hit the ground hard, and he gasped desperately for air.
"Compared to genuine destruction," Oboro observed with cold satisfaction, "you should consider yourself fortunate indeed."