Hiru did not stay long at Ubuyashiki's place. After confirming that the curse within Ubuyashiki's body was not spreading violently, he left once more.
But Tanjiro could not calm down so easily. He instinctively looked at Ubuyashiki, who still sat steady and unmoving behind his desk. After opening his mouth several times, he finally spoke.
"Um, Oyakata-sama…"
"Hmm. Have you discovered something else, Tanjiro?"
"No, nothing like that. Everything around us is very calm. I just… I just…"
"You just have some doubts about Hiru, is that it?"
Tanjiro nodded, then quickly remembered that Ubuyashiki could not see him, so he answered aloud.
"Yes. There's something I can't quite understand…
"When we first met, the demon scent on Hiru-san was extremely sharp, but after I calmed down, I could also remember a very gentle, sweet scent… What confuses me most is that every time we meet, there's no scent of lies on him. But the things he says are just too unbelievable."
"Hmm, that is true." Ubuyashiki smiled gently. "Although it is difficult for us to build trust, our stance toward Muzan is completely the same… And though he has never said it outright, Hiru seems to hold a conflicted attitude toward the fact that he is a demon."
"Huh? Does he?"
"Yes. Sanemi spoke to me about it in private." Ubuyashiki lowered his gaze. "Ever since Hiru bit him that day, Sanemi has been paying attention to Hiru's movements. He said that although Hiru constantly talks about wanting to drink blood, he absolutely will not act without Sanemi's consent. And even after receiving it, he only takes a small, shallow bite. He shows great restraint.
"Shinobu also told me that during one of her conversations with Hiru, he once described her as 'junk food he doesn't want to eat.' He openly admits he is a demon, yet resists certain instincts that come with being one… Perhaps this, too, is a path left open by heaven."
Tanjiro still did not quite understand, but just as he was about to speak again, a thunderous roar came from outside, as if the sky had collapsed and the earth had split apart. The tremor beneath his feet was so strong that he could barely keep his balance. After quickly checking that Nezuko and Tamayo-san were unharmed, he rushed to Ubuyashiki's side and reached out to support him.
"Thank you." There was not the slightest trace of panic on Ubuyashiki's face. "Could I ask you to go outside and see what happened, Tanjiro?"
"Yes! Please hold on steady! I'll go check right away!"
But when Tanjiro opened the door and saw the towering crystal castle in the distance reflecting the moonlight, he found himself unable to say a single word to describe what he was seeing.
"…Tanjiro?"
"Ah, yes! A massive crystal fortress has appeared on the distant mountaintop! It's incredibly beautiful and overwhelming! But I can tell it's collapsing!"
"A crystal fortress…" Ubuyashiki lowered his head and thought for a moment. "Tanjiro, what time is it now?"
"Yes, I'll go check… It's 3:30 a.m."
"At this time of year… there should be less than two hours until sunrise." Ubuyashiki turned toward the direction of the breeze. "I only hope this battle, which should not have dragged on for so long, will not be delayed any further…"
Tanjiro froze, unable to fully understand what Ubuyashiki meant. He simply smiled and said, "It's all right. As long as we wait until sunrise, we'll be able to defeat Muzan!"
Ubuyashiki lowered his gaze.
"Yes… Once the sun rises, everything will be settled."
...
The moment Muzan saw Hiru, he recognized that the person before him was also a demon, and not one he had transformed himself.
Over the past several hundred years, the only one who had ever broken free from his control was Tamayo, and Tamayo hated him with all her being…
At that thought, Muzan's eyes darkened slightly.
"Are you a demon created by Tamayo?"
Perhaps because he had already succeeded once in sending Muzan to hell, Hiru found himself unexpectedly calm while facing him. Hearing the question, he only gave a slight shrug.
"No, though I do get along fairly well with Tamayo-san. Well, well enough, I suppose."
Muzan's plum-red eyes fixed on Hiru. After a moment, he spoke again.
"Why help humans? Those ungrateful, inferior creatures will turn their blades on you as soon as they are done dealing with me…
"I admire your abilities, and I can overlook your earlier insolence. So, will you become my subordinate? As proof of your loyalty, all you need to do is tell me Tamayo's whereabouts."
Hiru merely tilted his head and looked at Muzan.
"Sometimes I really do think you're strange. You're outrageously arrogant when you should be enduring, yet you can speak calmly when you shouldn't be enduring at all… Do you have a masochistic streak or something?"
Muzan's expression instantly darkened, and hideous bone whips extended from his back.
"…You ungrateful scum."
"Getting angry already? Your temper really hasn't changed at all." The smile on Hiru's face widened despite himself, and signs of demon transformation began to surface across his body. "Sure enough, I still think you looked better when you were shattered into one thousand eight hundred pieces~"
Muzan's face turned black with fury. As he attacked Hiru, he was also secretly shocked.
Hiru's words undoubtedly meant that he had seen Yoriichi back then. He might even have been nearby at the time. In other words, he was not a demon created by Tamayo. He had become a demon on his own!
[Is he also a Primordial Demon…?]
Muzan looked at Hiru, who had been forced into doing nothing but dodging, and his expression turned vicious.
[I cannot leave him alive!]
...
"What the hell is that demon trying to do?!" Sanemi slammed his fist against the crystal barrier beside him in irritation. "Is he trying to trap us here until we die?!"
"Well… looking on the bright side, maybe he just wanted to stock up on some emergency rations?" Tengen touched the scratches on the crystal wall, looking quite interested in the structure before him. "And strictly speaking, without this layer of crystal, we would have already died under that crystal city that suddenly appeared and then came crashing down."
"But didn't he make this crystal wall too?" Muichiro tilted his head. "Though it really could be just like Uzui-san said, only for stocking up on…"
Before Muichiro could finish, a thunderous shattering sound erupted beside them. The Hashira saw a figure smash through the crystal wall at incredible speed, then slam into the opposite wall just as violently.
They could not help looking at the person sprawled amid the shards, covered in blood. Tengen's mouth twitched.
"…Did you come here to deliver us your head?"
Hiru rolled his eyes and let his broken bones regrow, but he did not hurry to stand.
"Deliver my ass. I couldn't beat him. Did you seriously expect a useless fighter like me to take down Muzan? Shift change!"
The Hashira: …