"It was Lucien who killed them. I smelled everything."
Before Shinobu Kocho or Mitsuri could react, Nezuko—still clutching Tanjiro's lifeless body—burst through the window and threw herself into the sunlight.
A piercing scream tore from her throat. Her skin blistered and melted instantly, steam rising as if she were being burned alive from the inside out. Her entire form writhed and twisted in agony, yet despite the unbearable pain, she refused to let Tanjiro's body fall from her arms.
She staggered forward, scorched and trembling, driven by a single instinct. To take Tanjiro home. To lay him to rest. Then to avenge him.
Behind her, Mitsuri and the others froze in shock. They had witnessed countless horrors as Pillars, yet nothing prepared them for this. Nezuko was running under the sun. Even though her flesh burned with every step, she did not turn to ash.
"How is this even possible?!" Mitsuri's voice cracked, her eyes wide with disbelief. A demon—walking, screaming, suffering—yet still alive under the scorching light.
Shinobu and Kanao shared the same stunned expression. Their understanding of demon physiology shattered before their eyes.
Hours later, Mitsuri and Shinobu arrived at Demon Slayer Corps Headquarters. The Pillars gathered under a heavy atmosphere. Mitsuri's worry made her face puff slightly, her emotions simmering.
"I don't believe what that demon said. If Lucien wanted to kill Tanjiro and the others, he wouldn't have risked his life to save them on Natagumo Mountain." Mitsuri clenched her fists. "Shinobu, what do you think?"
Oyakata-sama gently raised his hand, signaling her to calm down. He turned toward Shinobu quietly.
Shinobu, discarding her usual gentle smile, lowered her gaze.
"Kanzaki Aoi and the others said they heard nothing. No struggle. No footsteps. No signs of a fight. Tanjiro and the others didn't even resist…." Her meaning grew clear without needing further words. She hadn't believed Nezuko at first. But with the lack of evidence to point elsewhere, Lucien had become the strongest suspect. Unless a demon had appeared—but that was impossible. Demons could not appear in full daylight.
"Haha, then let's solve this face-to-face." Kyojuro spoke boldly, as straightforward as ever.
"But the problem," Obanai Iguro added sharply, "is that the man has vanished."
His mismatched eyes flicked toward Mitsuri. She looked distressed, her lips pressed together anxiously. A stab of jealousy twisted in Obanai's chest. He had admired Mitsuri quietly for so long, yet ever since Lucien appeared, she behaved differently.
"Master," Gyomei murmured tearfully, palms pressed together, "that demon girl… Kamado Nezuko… did she truly survive beneath the sun?"
"It's true." Shinobu nodded firmly. "We saw it with our own eyes."
Oyakata-sama smiled faintly, as though understanding something deeper.
"It is the strength of family bonds."
The Pillars stiffened.
"This is humanity's greatest light. It's because of that bond she has never eaten a human." Oyakata-sama spoke softly. "Her love for her brother has carried her beyond the limits of demons."
He had learned this from Tanjiro's mentor. It was why he planned to gather the Pillars to conduct a judgment for Nezuko and Tanjiro together. But that future was gone. Now, with Tanjiro dead and Nezuko awakened through agony and grief, everything had changed. Hatred could be just as powerful as love.
"Master… do you believe Lucien is the murderer?" Mitsuri's voice trembled. She didn't understand. Did they truly think the demon was telling the truth?
Oyakata-sama remained silent. But that silence was an answer. From the very first moment he met Lucien, he had sensed something. Something heavy, something painful. He wanted to help Lucien the same way he guided the Pillars, but time had not allowed it.
Everyone carried a past. Everyone faced crossroads. One thought could lead to redemption—or ruin.
"I will investigate this myself." Mitsuri bowed deeply, then ran from the room. It was the first time she had ever been disrespectful in front of Oyakata-sama.
"Mitsuri." Obanai stood abruptly, wanting to chase after her—but he hesitated.
"Go after her," Oyakata-sama said gently.
Obanai bowed. "Please excuse me, Master."
After he left, the room grew heavy once more. The next threat to the Demon Slayer Corps might not be Muzan alone.
Meanwhile—inside the twisted architecture of Infinity Castle—the eerie chime of a biwa echoed. Upper Moon Six, Daki, appeared kneeling before Kibutsuji Muzan.
"You failed."
Muzan's plum-red eyes held no emotion, only cold authority.
"When I arrived at Natagumo, the battle was already over," Daki answered quickly. "Lower Moon Five may have been killed by the Demon Slayer Corps."
"Rui is alive. I can sense him." Muzan's tone was indifferent. "Both Rui and that demon Nezuko have undergone drastic changes. You have ten days to find him."
"Yes." Daki bowed deeply, sweat sliding down her forehead.
"Go."
The biwa played again, removing her from the chamber.
Soon after, the five remaining Lower Moons—Enmu, Rokuro, Gyuu Mooo, Mukago, and Kamanue—received Muzan's command. Find Nezuko.
As for the five Upper Moons, they had already scattered in all directions, hunting for one individual: Lucien.
Outside, danger stirred like a brewing storm.
Lucien, however, was immersed in training.
Deep within a mountain gorge, wearing only his boxers, Lucien stood beneath a waterfall forty meters tall. The water slammed against his shoulders with crushing force, turning his skin red and bruised.
He endured it for an hour before stepping out, steady and calm despite the pain. Sitting on a smooth rock, he drew his golden Nichirin Blade.
With focused breath, he channeled his Ki into Thunder Breathing. Heat spread through the blade, its once ten-degree temperature rising steadily. Ten degrees. Fifteen. Twenty.
Once again, he hit the same barrier. The next threshold demanded more precision, more strength, more control. Through the constant application of Ki, his mastery had sharpened drastically.
Time passed like sand through fingers. Three months slipped by. In that time, Lucien isolated himself completely, dedicating every hour to cultivation. Three monthly rewards yielded a bag of sea salt, a barrel of Arowana oil, and a bottle of aged vinegar.
Now, floating cross-legged in the gorge, Lucien's amethyst eyes calm and steady, Ki flowed freely around him. By channeling it through every vein and muscle, he discovered he could lighten his body—lift himself—move through the air as though gravity held no weight on him.
He could fly. Not with Geppo. With pure Ki refinement. It reminded him of the Sky Dance technique from Dragon Ball. Simple. Elegant. Free.
Steadily, Lucien conjured a white T-shirt and green beach shorts over his boxers, then exhaled smoke after taking a long drag from a cigarette. He looked across the gorge he had called home for months. Three months of silence was enough.
It was time to move. He had no idea what awaited him outside.