The next day, on their way to Edo Castle, Oboro and his maids stopped in a small town.
As daybreak approached, golden light appeared on the horizon. Because Muzan's cells had transformed his flesh and blood, Oboro felt an instinctive fear when he looked at the brightening sky. Everything in him screamed to flee into the shadows.
The stronger the sunlight grew, the greater the fear clawing at his heart became.
But Oboro didn't run. He stood perfectly still, his eyes calm and resolute.
Some families in the town had already begun their daily tasks, stirred awake by the early morning. As the sun rose in the east, night gradually retreated, and the cold dissipated. Wisps of golden light fell upon the pedestrians in the street, including Oboro.
It stung, it stung terribly.
It felt as if molten iron were being poured over his body. The skin on his face began to peel and melt away.
The maid beside him covered her mouth in horror at the sight.
But Oboro remained calm. Despite his strong spirit, this didn't compare to when he had wandered the Dark Continent in his previous life. His vulnerability to sunlight stemmed from Muzan's genes. His Hatsu could suppress the cells' abilities but couldn't alter their fundamental properties. Sunlight remained his natural enemy, something he couldn't resist with his soul alone.
Now, he needed to verify whether the blue spider lilies he had consumed earlier would work.
Witnessing the noble warrior in the black haori suddenly begin to disintegrate, his flesh burning as if consumed by fire, made passersby turn pale with fear and flee one after another.
"Master!"
Chiyoko snapped out of her shock and rushed forward to wrap her arms around Oboro. She used her body to shield him from the sunlight, desperate to prevent further harm.
Following Chiyoko's example, Rina quickly came to her senses and moved to protect him as well.
"It's fine."
Oboro smiled gently and patted their shoulders. The parts of his body that had been scorched by the sun stopped burning and stopped smoking. Only shallow scars remained. He could feel a peaceful, warm force flowing through his bloodstream, repairing the damaged cells. As the cells healed and regenerated, his body no longer reacted to the light.
The power of the blue spider lily.
Indeed, this was the key.
However, as the lily's effects cleansed his cells in a "purification" process, they removed the demonic aspects. This return to normal instantly weakened his enhanced attributes, and he lost the demonic transformation.
He no longer possessed a demon's power.
When the lily took effect, Oboro tried to use his willpower to retain some of Muzan's genes, but only a tiny fraction remained. Any more would have triggered a reaction, causing his flesh to burn in the sunlight once again.
Therefore, his current state was mostly that of a human being.
The only difference was that, since he retained a small amount of those genetic cells, his physical strength was slightly greater than that of ordinary people, though not dramatically so.
His ability to regenerate entire limbs or grow flesh from exposed bone, a demon-like ability, was now beyond him.
Nevertheless, Oboro had achieved his goal. The disease that had plagued his body was eliminated by this transformation. Now, he had nothing to worry about when it came to training or refining his body.
What surprised Oboro was the behavior of his two maids. He thought seeing his ruthless side would scare Chiyoko and Rina, causing them to keep their distance, even if they followed him out of necessity for survival.
It seemed that wasn't the case at all.
Humans truly were emotional creatures. Bonds formed from growing up together were difficult to break.
This was the warmth of humanity.
In Oboro's mind, the image of the Firth Lily flashed unbidden. That woman's feelings for him in his previous life were similar. But Oboro hadn't cared then. He hadn't taken her feelings to heart. Their relationship had begun as an exchange of interests, so he valued her usefulness more than her feelings.
Now, he was the only one who could preserve this limited number of Muzan's cells. When a powerful being from a higher realm descended to a lower world, certain things became possible.
"Even with the blue spider lily, it seems immortality remains out of reach."
Oboro laughed softly.
This outcome stemmed from the opposing natures of the spider lily's power and Muzan's cells.
If Muzan were to consume a large quantity of blue spider lily, he might revert from demon to human.
For him, that transformation might be more painful than death itself.
Muzan was also the last remaining seed in the world who could activate the power system. After all, Yoriichi Tsugikuni was gone. Therefore, even if the will of this world secretly governed everything, it was impossible for Muzan to obtain the blue spider lily.
If Muzan took the lily, his seed would lose its value.
Back then, the prescription the doctor gave Muzan was similar to mine. The doctor hoped to restore Muzan's vitality with the power of demonic transformation and then use the blue spider lily to return him to humanity. The doctor's intentions were good, but he never realized that beneath his human appearance, his patient was actually an evil demon."
Oboro contemplated silently.
Before taking the blue spider lily, Muzan killed the doctor.
Someone like Tanjiro, who eventually absorbed Muzan, could transform completely into a demon, become immune to sunlight, and emerge as the new Demon King. Such a path was theoretically possible. However, Tanjiro's willpower was too weak. Even as the Demon King, he couldn't think coherently. Muzan's consciousness would always linger in his brain and soul.
It would have been natural for Oboro to let the red spider lily fulfill its purpose and absorb all the demon power.
But he didn't want that. The power he now possessed no longer required demonic enhancement.
His mentality had changed since his previous life.
If he had first traveled through the Demon Slayer world, he might have sought the "living" state Tanjiro achieved after devouring Muzan. However, that would have been no different from evolving in the Dark Continent. Even then, Oboro had not actively chosen to evolve.
He always tried his best to maintain his human identity even though he had already transcended the category of human life.
Tanjiro could become the new Demon King, but Muzan could not, even if he obtained the spider lily. The reason was simple. Although Muzan was the ancestor of demons, Oboro discovered his soul was empty.
The demon lord had deep obsessions, great desires, and towering ambitions, but his mental strength paled in comparison to Tanjiro's, not to mention some of the Hashira's.
Obsession is just obsession; it doesn't represent the fullness of will.
In short, Muzan lacked true strength of heart.
His power manifested only through demonic abilities granted by his genes, not from within himself.
After experiencing the effects of the spider lily, Oboro was certain that Muzan would regress rather than evolve if he took it.
"To improve your power system, you must evolve it, but you need the right vessel."
Oboro murmured softly.
"Let's go."
Then, he withdrew his gaze from the rising sun and smiled at the two maids.