In the end, only a few of the giant corpses were stored away in Rei's Misty Ring.
That said, it was strictly for the purpose of researching what kind of beings the giants were—not for materials or food, as Byune had suggested.
This was, for Rei, the absolute maximum concession he was willing to make.
Leaving behind the Underground Fourth Floor littered with giant corpses, Rei and his party made their way back down to the Underground Fifth Floor.
However, unlike their first visit, there wasn't a single giant left on the Underground Fifth Floor.
Rei's plan to lure every last giant up to the Underground Fourth Floor and defeat them there had hit the mark perfectly.
"...Looking at it like this, there's nothing particularly mysterious about that Black Crystal, is there?" Vihera muttered, gazing at it from the staircase.
Indeed, looking at the Black Crystal now, there was no sense of anything being off. Just as she said, it appeared to be nothing more than an ordinary black crystal.
But... Rei knew that was merely a facade.
The Black Crystal showed no activity simply because there were no giants around. They had originally lured the giants up to the Underground Fourth Floor for exactly this reason, so the situation was going according to plan... but still.
"Anyway, let's head down the stairs. We don't know what it might do, so stay alert and be ready to respond to anything at a moment's notice."
If what awaited them on the Underground Fifth Floor were humans or even monsters, predicting what actions they might take wouldn't be impossible.
But their opponent was the Black Crystal—an unknown entity.
If he carelessly touched it and it triggered the black snow he had just witnessed falling... thinking of that, Rei couldn't possibly act recklessly.
Of course, what would actually happen if he touched that black snow was something even Rei didn't know.
I have the Dragon Robe and all, so I think I'd be fine unless something extreme happens. But even so... honestly, I'd rather not if I can help it.
He thought this while staring at the Black Crystal, but that didn't mean he could just stand here forever. Eventually, Rei inhaled, steeling himself, and began descending the staircase.
"Hey, what should we do?" Marina called out to him from behind.
Rei glanced back only for a moment before speaking. "We don't know what's down there, so keep watch from there for now. If you notice anything, just let me know."
"Understood. Be careful."
After Marina's words and similar warnings from the others, Rei continued down the stairs. Stepping onto the floor of the Underground Fifth Floor, he once again surveyed his surroundings.
"It's completely different."
That was Rei's honest impression after looking around. Down through the Underground Fourth Floor, everything had been properly maintained, with floors and walls no different from a building on the surface.
But this Underground Fifth Floor was left exactly as it had been after being dug out of the earth.
The scene gave the impression of a cave, and Rei naturally had questions.
In the first place, the Black Crystal was supposed to be an extremely important object for Jaya. The place where such a Black Crystal was kept should naturally be properly maintained.
Which means there's a reason it needs to be like this...? Well, it would be strange otherwise, I suppose. Still... hmm.
Harboring these questions, Rei looked around once more. There was nothing particularly noteworthy—not even a single surviving giant remained.
"For now... I guess I just have to try it myself."
Given that the floor was in its excavated state, the surrounding earth was naturally exposed, with small stones scattered about. Perhaps because the giants had passed through many times, the dirt on the ground was visibly packed solid.
Just how many giants had come here? For that matter, why had the giants been curled up around the Black Crystal when Rei and his party first arrived on the Underground Fifth Floor?
No, really, why was that?
Rei had questions, but the answers would likely remain unknown unless he directly investigated the Black Crystal. Making that judgment, he began approaching it, little by little.
With each step closer, something emanating from the Black Crystal grew stronger. What it was, what kind of presence it was... even Rei didn't know, but there was undeniably something there.
Aware of this, Rei nonetheless continued closing the distance.
"Hey, Rei. Is it really okay to walk straight toward it like that!?" Marina's voice reached him from behind, but to his current self, those words held no meaning.
Dominated by emotions he couldn't even comprehend, he approached the Black Crystal...
"Rei, can you hear me!? Rei! Hey, are you listening!?" After Marina, the next voice he heard was Vihera's.
Listening to that voice, Rei finally arrived right beside the Black Crystal... and gently reached out his hand.
"Rei!"
With a jolt—Elena's voice, the last thing he heard, stopped Rei's movement for an instant.
But by the time his movement halted, Rei's hand had already touched the Black Crystal.
In that instant... as if some switch had been flipped, Rei completely lost all sense of where he was.
No—he couldn't even comprehend who he was anymore.
The surrounding scenery was no longer the cave-like underground floor from moments ago, but an expanse of solid black stretching endlessly in all directions.
Space? ...No, what is space? For that matter, who am I?
Without even realizing that he could no longer speak, he simply looked around. He didn't even remember that he had been touching the Black Crystal seconds ago, nor could he understand why he was here.
He couldn't even remember who he was—a phenomenon that, under normal circumstances, would be utterly incomprehensible.
And yet, Rei's mind showed no agitation; on the contrary, he was calm to a degree that even he found strange.
I am, this place is... what exactly? Where am I? For that matter... hm?
Rei was in a state of calm confusion—a near-contradiction—when he suddenly noticed something.
The density of the darkness surrounding him was increasing.
Since it was a darkness that could aptly be described as pitch-black, an increase in density or concentration shouldn't make much apparent difference. And yet, for some reason, Rei could sense that the darkness around him was growing thicker.
What? What's happening? No, what is this in the first place...?
Not knowing who he was, where he was, or what situation he was in. In such a state, the darkness around Rei grew even more concentrated... the gaseous darkness became so dense that it liquefied... and then, upon touching Rei's body, it began to seep in.
What this specifically meant, Rei didn't know, but he understood that it was an unfavorable phenomenon for him.
However, even understanding that, he couldn't grasp it as something genuinely dangerous. That dissonance in perception left him unsure of what to do...
Grrrrrrrrr!
Suddenly, such a sound echoed through the space from out of nowhere.
Even as he was being eroded by the darkness, still unable to feel any sense of crisis, Rei looked around to see where the voice had come from. But in a space where only liquefied darkness existed, looking around couldn't possibly help him understand what was there.
Was it his imagination? Rei wondered, but once again, a voice came from out of nowhere.
"Rei, what are you doing! You're with me, aren't you!"
A clear, dignified voice echoed through the surroundings once more.
The moment he heard that voice, Rei looked around again. But, naturally, there was no sign of anyone. There was only the dense, pitch-black space around him—nothing else.
There was nothing. He understood that, and yet, judging by the voice he just heard, he couldn't help but feel that there was something out there.
What is this inside me? ...Something warm, yet a vivid golden light. Wait, warm? What does that mean? Golden? What does that mean? What am I thinking? What exactly is going on?
Something within himself. Something he should understand, yet didn't. Rei could do nothing but be bewildered by it.
But that something was undeniably important to him... something irreplaceable, and yet he couldn't even grasp what "important" meant.
"Rei, what's wrong? We're having a party at my place today, right? After that, I'll teach you how adults spend the evening, so look forward to it."
The voice came again. That smooth, sultry voice brought calm just from hearing it... and yet simultaneously stirred a contradictory restlessness.
But of course, he had no idea what those feelings were, and all Rei could do was flounder in confusion.
He understood that the emotions within him were irreplaceable, but he couldn't comprehend the feeling of "irreplaceable" itself.
"Rei, I'm going to win our mock battle today! If I win, let's go to the river. In exchange, if Rei wins, I'll go along with you on a food stall crawl."
The voice he heard for the fourth time. That spirited voice generated a mysterious vitality within Rei.
Without knowing what that vitality was, Rei nonetheless turned his thoughts to something that had welled up inside him.
What is this, exactly...? I am, I am, I am... what?
Only bewilderment arose and faded within Rei. And as it faded, it was born anew, only to fade again.
How many times had this repeated? Even Rei didn't know. No, he wasn't even aware of what he was doing. It was an entirely unconscious action.
But still... the fact that he desired it meant it was something important to him... somewhere in his heart, he must have understood that.
Pulled by something within himself... no, it wasn't something so simple—he was being drawn in, as if sucked toward it.
Rei didn't consciously recognize its existence. He didn't—and yet, somewhere in his heart... no, in his unconscious, he understood that it was irreplaceable to him.
Though he had no awareness of it whatsoever, Rei still sought it... and the darkness around him, as if refusing to lose to that something, accelerated its erosion into Rei.
Rei had no awareness of it at all; he simply existed in silence, gazing at the dark space around him. But within Rei, the light inside him and the darkness surrounding him were locked in a balanced struggle.
Light... what does warm mean? Darkness? What does dark mean?
Whether he was aware of what was happening inside him or not, Rei simply existed within the space of darkness.
Whether he was standing, lying down, or floating—he didn't know what state he was in, but even in such a situation, there was no confusion.
No, in fact, the very concept of confusion was something the current Rei probably couldn't even comprehend.
In a sensation like drifting through darkness, Rei simply stared quietly at his surroundings.
In that state, however much time passed... Rei couldn't even comprehend the concept of time, but even if he could, he wouldn't have known whether it had been a minute, an hour, a day... or even a month or a year since he entered this dark space.
Rei simply drifted through the darkness, doing nothing.
During that time, the battle between light and darkness continued to rage within Rei, though he himself couldn't comprehend it at all.
But... in the midst of that situation, a voice once again echoed inside Rei.
"Rei!"
Multiple women's voices overlapped, and among them was a grruu that somehow felt as though it too was calling Rei... and the moment he heard that voice from within himself, Rei instantly understood who he was and what situation he was in.
"I am..."
The first actual words spoken since being trapped in this space of darkness.
And the instant Rei's voice left his own mouth, he finally understood the darkness that had been trying to erode him from within.
Rei's response after comprehending that darkness was swift.
"Disappear... the darkness inside me... disappear!"
Along with those words, an enormous amount of magical power erupted from Rei.
Flame Emperor's Crimson Armor—the skill with the greatest destructive power among all the skills Rei used.
And as the skill activated... in the next instant, the darkness within his body, the darkness surrounding him, and the very space filled with darkness itself were all incinerated by flame.