Hiru never expected that even after running away so decisively, he still could not shake off Kokushibo. Honestly, if not for the years he had spent "alive" in Hell, and if Michikatsu-aniue had given up on teaching him martial arts the way Yoriichi-aniue had, allowing Hiru to become somewhat familiar with his attack patterns, then right now, he would truly be running with his head in his hands.
But in that brief moment of distraction, Hiru felt a sharp pain in his calf. His balance went completely off, and he pitched forward. Fortunately, he reacted in time, planting both hands on the ground and using the momentum to flip himself over and stand back up.
This time, however, he did not keep running. Instead, he turned around somewhat helplessly and looked at his severed leg.
"Aniue, you really don't hold back at all. But forget it. After all, the current you doesn't know me."
"Who... exactly... are you?" Kokushibo slowly walked forward. "Very... suspicious."
"I do like reminiscing too, but right now..." Hiru shrugged slightly. "Let's not, for the time being. After all, killing Muzan is my main goal.
"Hiss... Now that I think about it, this medicine could be developed in another direction too, couldn't it? How does that saying go? Killing Muzan feels good for a moment, but desecrating his corpse forever feels good forever!
"Mm, when I get back, I should have Tamayo-san change her research direction. I feel like Michikatsu-aniue and Yoriichi-aniue would like it too..."
Kokushibo: ...What kind of nonsense is this?
After confirming once again that the demon before him only knew how to mutter insane nonsense, Kokushibo hesitated no longer and charged forward with his blade again. But when the edge cut through Hiru's body, the only sound was the shatter of crystal.
"That was close, that was close."
Kokushibo turned back and saw Hiru watching him from behind a wall made of crystal, a harmless smile still on his face.
"Although taking Aniue out for a walk is pretty fun, I have something more important to do right now. After all, I found that space demon. I need to bring her over before Muzan realizes what's going on, so I'll leave Aniue here by yourself for a while! Once I control that demon and bring Muzan over, I'll come back and take you to watch the sunrise together!"
Kokushibo silently slashed at the crystal wall again, only to find that this time, its hardness was on a completely different level from before. His strike only knocked loose a little crystal dust.
Watching Hiru's figure vanish at high speed, Kokushibo looked around at the crystal walls that had completely surrounded him. He withdrew his long sword and began trying to contact Muzan and Nakime.
But after several attempts, he had no choice but to admit one thing.
He had lost contact.
Clearly, the problem did not lie with him. If there was anything different about him compared to before...
Kokushibo's gaze fell once more on the crystal walls enclosing him, and he looked rather speechless.
[...Developing a Blood Demon Art with such a pointless effect. No wonder he only knows how to run away.]
...
Tanjiro tucked the blanket around his younger sister, who had fallen into a deep sleep. When he looked up again and saw Tamayo-san in front of him and Ubuyashiki smiling beside her, he felt so awkward he wished he could take Nezuko and move to another room.
"There's no need to be nervous. The medicine injected into your sister was tested beforehand. It can turn demons back into humans."
"I'm truly grateful to you, Tamayo-san, but..." Tanjiro withdrew his furtive glance from Ubuyashiki and looked at Tamayo, speaking softly with some hesitation. "Is the current situation really all right?"
Tamayo raised her eyes to look at him. After a moment, she lowered them again.
"Given the current situation, those things no longer matter. This guilty body of mine has only lingered on until now for the sake of eliminating Muzan. My lifelong wish is simply to watch that man go to hell."
Tanjiro was about to say something more, but the scent that suddenly reached his nose startled him. He instantly sprang up, pressed a hand to his sword hilt, and looked toward the door.
Sure enough, in the next second, Hiru's helpless voice came from outside.
"Seriously, is that nose of yours really something a human should have?"
Tanjiro's shoulders relaxed slightly, but his expression remained extremely wary.
"Were you not fighting together with the Hashira?"
"Mm, the objective should be accomplished, so I came to get a few things."
Hiru patted Tanjiro on the head.
"Now then, Tamayo-san, how is the medicine I mentioned before?"
Hearing this, Tamayo took a sealed syringe of medicine from the medical kit beside her.
"Although I did make another dose of the medicine that can turn demons back into humans according to your instructions, forgive my bluntness, but you yourself are also the Demon King. A general medicine of this level would have great difficulty taking effect on you."
Hiru took the medicine, pushed out a tiny drop onto his finger, rubbed it lightly, then held his hand in front of Tanjiro.
"Does it smell the same as the one given to your sister?"
Tanjiro froze, but still leaned in and smelled it seriously. Then he nodded slightly.
"It's the same. Hiru-san?!"
Hiru ignored the stunned Tanjiro, casually threw away the empty syringe, and supported Tamayo as she fell completely unconscious under the effect of the medicine. He laughed softly.
"This time, go back to being human properly. After all, you've already spent several hundred years atoning. There's no need to rush to hell over a few decades. Hey, Yushiro, you're definitely nearby, aren't you?"
Yushiro, who had been quietly hiding in the corner under the cover of his Blood Demon Art and was just about to leap out and attack: ...
"It doesn't matter if you don't come out now, but after Tamayo-san wakes up, you'd better obediently inject the medicine too, understand? Otherwise, don't blame me for separating you two between life and death."
Hiru swept a glance toward the corner and sneered.
"Remember, this is not a joke... Do you understand what I mean?"
Yushiro: ...Doesn't that mean I can live with Lady Tamayo for several decades as a human? Great!
"Ahem... When Tamayo mentioned the medicine to me, I thought Hiru intended to use it himself..."
Hearing the voice, Hiru turned to look at Ubuyashiki.
"No way. I still want to take another bite of Shinazugawa when Muzan dies, so I can savor the memory when I return to Hell. If I turn back into a human, I won't be able to eat that addictive flavor anymore."
"I see..." Ubuyashiki wore a gentle smile. "Then how is Hiru's plan progressing?"
"As for the plan..."
Hiru laid Tamayo down steadily beside Nezuko, then found a place to sit cross-legged.
"It's going fairly smoothly, I suppose?
"I've already controlled Michikatsu-aniue and the demon with the Spatial Blood Demon Art. Muzan has also been tricked into the Infinity Castle by me. Right now, Himejima and the others are evacuating the civilians in that area. After all, once the furious Muzan kills that space demon, the Infinity Castle I've fully crystallized will collapse into the real world. After that, if we stall him a little, it should be dawn...
"Ah, right. Remember to handle the post-battle compensation. I'm completely broke right now and can't afford to pay reparations."
"...What exactly is the affected range?"
"Mm. Your original mountain, plus the towns in a ring around the foot of the mountain. No, make that two rings? Although Muzan's location is only one small point, that Infinity Castle really is huge..."
Hearing this, Ubuyashiki let out a slight breath of relief. If it was only to that extent, then...
"Ah, one more thing. Because I converted the entire Infinity Castle into crystal, once it collapses into the real world, you may also have to deal with rumors about a 'ghost castle' or something like that."
Ubuyashiki: ...