"Swoosh, swoosh."
Several shadowy figures flew in from a distance. Their expressions darkened when they saw the battered battlefield.
"Why did he not come?"
Muzan surveyed the eleven demons kneeling before him. One was missing—Lower Moon Five, Rui.
"I cannot sense his location," Narime whispered, her long black hair hiding her face.
Muzan closed his eyes, concentrating. After ten seconds, his plum-red eyes snapped open, full of disbelief and rage. He had lost contact with Rui—just as he had lost control of Tamayo and another demon associated with the Demon Slayer Corps.
"He is not here," Muzan growled. "Daki, go to Mount Natagumo and find Rui. All of you, Upper Moons, kill that man from the Demon Slayer Corps for me."
He paused, his eyes narrowing.
"He has short black hair, a scar on his forehead, stands about 1.73 meters tall, has a pale complexion, and a pair of purple, diamond-patterned eyes."
"Is he a Hashira?" asked Upper Moon One, Kokushibo, his six eyes glinting with curiosity.
"No," Muzan replied coolly, "but he is stronger than one."
"Understood. We depart!"
With the strum of Nakime's biwa, every Upper and Lower Moon vanished. Sending five Upper Moons after Lucien Graves was unprecedented in centuries—but Muzan feared him. He feared that Lucien could become another Yoriichi Tsugikuni, and he would eradicate that threat at any cost.
---
At the Demon Slayer Corps Headquarters, all the Hashira knelt on tatami mats—Oyakata-sama and Amane kneeling opposite them. Oyakata-sama had just heard the full report.
"Mitsuri-san, you are kind and honest, so when you lie, you lower your head and your fingers drift aimlessly," he said with a gentle smile, no hint of reproach.
Flame Hashira, Kyojuro Rengoku, blinked.
"Mitsuri-san, are you lying?" he asked softly.
Sound Hashira, Tengen Uzui, glanced at Mitsuri's hands. He seemed surprised.
Gyomei Himejima, tears still staining his cheeks, looked at Mitsuri earnestly.
"Mitsuri-san," Oyakata-sama said, "You didn't do it, did you? It was Lucien Graves who drove away Muzan."
Tears welled in Mitsuri's eyes, and she hesitated. Then she spoke quietly:
"Yes. I was evacuating civilians, but Lucien fought Muzan with his bare hands."
There was a stunned silence. The group exchanged shocked glances—the man Sanemi had easily defeated could face Muzan without a blade.
"You say he used bare hands?" Tengen repeated.
"Yes," Mitsuri admitted, breath trembling. "Lucien said a Nichirin Blade would not hurt Muzan…"
She told them everything, trembling, her fingers twisting unconsciously.
After she finished, the room was so silent you could hear a single breath. Fear, hope and awe mingled in every face.
"The opportunity to kill Muzan has finally come," Oyakata-sama whispered, his voice full of resolve. "Mitsuri, bring Lucien here when he recovers. There is something I need to ask of him."
"I will," Mitsuri replied, nodding firmly.
---
As dawn broke, Lucien lay on a futon in the Love Estate. Hanazawa and Sakura hovered over him anxiously.
"You suffered terrible injuries!" they cried.
"I'm fine," Lucien insisted, pushing himself upward. He planned to head to the mountain behind the estate to figure out how to turn his Nichirin Blade into a Crimson Blade.
"You really are okay?" Sakura asked, gently holding him down so he would not rise.
Lucien gave a wry smile.
"I healed on the way with Thunder Breathing," he said, peeling back his shirt to show his skin was unmarked. "See?"
Hanazawa and Sakura stared in disbelief. They had witnessed him being carried back, wounds bleeding, but now he looked completely healed.
An hour later, after a breakfast of simple rice and grilled vegetables, Lucien left for the waterfall at the back of the mountain.
He turned his golden Nichirin Blade over and over in his hands, deep in thought. He wanted to raise its temperature—to transform it into a Crimson Blade.
"Ho…"
He activated Thunder Breathing. Golden lightning crackled around him. He channeled all his strength into the blade.
"Crack, boom, zap."
The blade glowed red, as if thrown into a forge, its temperature rising. But it only rose by ten degrees before stalling. Despite all his effort, he could not push it any further.
Ten minutes later, Lucien panted, his sweat coating his brow. He looked uncertain. In that short span, he felt more drained than after the toughest training session — his stamina had collapsed far too quickly.
He sat cross-legged on a rock, scrutinizing the blade.
A ten-degree rise was nothing. A simmering pot, barely warm. If he really wanted a Crimson Blade, perhaps he needed the Demon Slayer Mark or to reach the Transparent World.
No, he thought. The fact that he raised it even a little meant something — with enough power, maybe he could raise it more. He just lacked the method or the conditions.
Lucien hardened his right hand, forming a crystalline aura that spread toward the Nichirin Blade. In sunlight, the blade's surface turned translucent, like polished crystal, coated with Haki, transforming into a crystalline longsword.
Its hardness was noticeably stronger. Lucien had researched this ability back in the Titan world — he had spent a year in the Titan realm honing what he called Hardening, and now he saw the resemblance: this was similar to Armament Haki in the Pirate World, though not exactly the same.
"Crack…"
Golden lightning surged again, and the crystalline blade glowed red under the Haki enhancement — but again, only ten degrees.
Frustrated, he raised his left hand, coating it with Haki. His palm began to glow a faint red. He concentrated, pouring power into it. The temperature rose just a little — again, about ten degrees.
He frowned, surprised by the result. Then he drew his kukri and infused it with his energy. But because the kukri was made of very hard material, its temperature barely changed.
He realized then: he could channel his body's power through Thunder Breathing into objects, heating them. Breathing techniques were not only for breathing — they acted like filters for his full strength.
He jumped off the rock and picked up a pebble. Imbuing it with energy, its temperature rose. He held a dry branch next — concentrated energy made it ignite spontaneously.
A smile curved his lips.
He felt he was onto something: if he could raise the temperature of his weapons — or even his own body — his attacks would be far more lethal. Not just slicing or piercing — but burning down to the cellular level.
The power was immense, but raising the heat was not easy.
Lucien clenched his fist, lightning flickering around him. The sweat on his skin cooled in the breeze, but his amethyst eyes glowed with determination.
He would master this. He would sculpt his blade in fire and lightning.