Tanjiro could only stare, wide-eyed and slack-jawed, at the two blurring afterimages streaking through the air—Ren Kuroda and Giyu Tomioka, locked in a battle far beyond anything he had ever imagined human beings were capable of.
Never, not even in his wildest dreams, had he pictured people moving with such monstrous speed.
Beside him, Nezuko whimpered faintly in pain. Seeing her expression, Tanjiro's heart tightened as Giyu's earlier words replayed in his mind. Did he really have the strength to protect her? Could he actually keep her safe in a world filled with beings like this?
Meanwhile, Giyu—locked in combat with Ren—grew increasingly unsettled. Even while using the Third Form, his fastest Water Breathing technique for pursuit, he could barely keep pace with Ren's movements.
And Ren's swordsmanship… it was far sharper and far more refined than Giyu had expected. Even though Giyu held the advantage, Ren's unnervingly calm expression throughout the fight made the Water Hashira feel a pressure he hadn't felt in years.
"So this is the strength of the Demon Slayer Corps? Or is it just you?" Ren asked casually between exchanges, his tone maddeningly composed. "Either way, good. Someone like you won't die easily. That means I don't have to hold back and worry I'll kill you by mistake."
At those words, Giyu's instincts screamed. His entire body tensed as he prepared to counter whatever Ren was about to unleash.
Whether Ren was bluffing or not didn't matter—Giyu knew that if he didn't take this seriously, he might not win at all.
But Ren wasn't bluffing.
Up until now, he had held back deliberately. He hadn't infused a single drop of his demonic power into his strikes. If he did… his swordsmanship would rise to a whole different level.
Ren slid to a stop in the snow, changing his stance abruptly. He gripped the ruined blade with both hands, and the air around him began to twist.
"People say the wind cuts everywhere… but the most violent force of all is still the wildfire that spreads without mercy," Ren murmured. "So witness it—the divine blaze, the ravenous flames of the fire wolf! Fierce as the burning wolf!"
Giyu's breath caught.
The temperature spiked—sharply, unnaturally. Snow hissed and liquefied beneath Ren's feet, then evaporated entirely as the heat intensified. Flames coiled along Ren's longsword—flames that should not have existed in this frozen landscape.
Then Ren swung.
A massive arc of fire roared forth, the inferno stretching wider as the wind fed it—like a pack of flaming wolves lunging to devour everything in their path. The heat and pressure were overwhelming.
This wasn't like Ren's earlier "Swift as the Wind."This was Fierce as Fire—and this time, infused with demonic energy.
Its power was not just higher. It was terrifying.
Giyu's eyes widened. His mind reeled.
Just moments ago, Ren had been using a technique almost identical to Wind Breathing. And now—this? Flames as destructive as those used by the Flame Hashira?
Could a single swordsman truly master two breathing styles?
Giyu had never heard of such a thing.
But now—right in front of him—Ren was displaying two entirely different sword forms:
One swift as a cutting gale.The other savage as a wildfire.
He had no time to process the impossibility.If he didn't react now—he would die.
"Water Breathing… Eleventh Form: Dead Calm!"
Water Breathing, like all fundamental techniques, traced its origins back to the Sun Breathing style. Giyu hadn't created the overall system—but as the Water Hashira, his individual talent was exceptional.
Eleventh Form: Dead Calm was his own original technique.
By emptying his mind and entering a state of absolute stillness, Giyu could nullify any technique that entered the radius of his blade. A tranquil barrier of flowing water manifested around him—an invisible domain where all incoming attacks were dissolved.
Of course, it wasn't invincible. If it were, he would be unstoppable.
But since creating it, Giyu had never once failed with this technique.
He believed in it now just as strongly.
The raging flames struck the tranquil waters.
Stillness versus fury.Water against fire.
Two natural opposites collided, exploding into a violent stalemate overhead. Ren's flames clawed forward, ravenous to consume everything. Giyu's water stood firm, defending its domain with unyielding resolve.
The clash froze in place, neither side breaking.Both fighters braced, exerting every ounce of strength they held.
Ren still had demonic power in reserve. Even if this didn't work, he still had one last trump card—his Half-Demon Transformation.
Giyu was at a similar decision point. He had never faced a demon of this caliber—and was considering whether to unleash everything he had to destroy Ren completely.
Both men tensed.Both hesitated.Both prepared to go all in.
Just then—
A sharp crack split the air.
Ren's already-battered sword—strained even further by the demonic energy coursing through it—reached its limit.
The blade shattered.
The aggressive flames, losing their anchor, seemed to give one last defiant howl before dissolving into the air.
And with Ren's power dissipating mid-clash, the delicate stalemate collapsed instantly. Energy spiraled out of control.
Shards of the broken blade burst outward like a shotgun blast—hundreds of fragments scattering in every direction.
Ren and Giyu could withstand such debris easily.
But they weren't the only ones here.
Tanjiro had no defenses—not against this level of battle.
His breath froze in his chest as he saw the deadly fragments hurtling toward him. For one terrified instant, he stood paralyzed—
Then instinct took over.
He grabbed Nezuko and pulled her into his arms, turning his back to the barrage.
If someone had to be struck—if someone had to bleed—
It would be him.
He would protect his sister, even if it cost him his life.