The massive crimson mana generated from Rei's core burned the Queen's body from the inside out.
It was an enormous surge of crimson mana, one that could safely be called orders of magnitude greater than what had been covering Rei's body through the Flame Emperor's Crimson Armor up until now.
The Queen had been having her body ravaged and burned from within, but that had ultimately been at the hands of the Flame Serpents—small existences, at least compared to Rei.
Even if it was the same kind of act, the scale was vastly different.
The tremendous crimson mana seared through the Queen's body, as if to mock everything that had come before.
"GIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII!"
The Queen let out an especially shrill scream.
She must have experienced pain that was incomparable to the Flame Serpents' attacks.
Rei's existence was undoubtedly the worst possible thing for the Queen.
How would she deal with him now that he was inside her body?
No matter what kind of counterattack she launched, Rei believed he could handle it in his current state.
In fact, even now, the Deep Flame radiating from his body was burning the surrounding flesh one piece after another, reducing it to charcoal and ash.
"Suffer. The Centaurs took casualties because of you. Feel at least a fraction of that pain. ...Well, you probably can't understand what I'm saying anyway."
Naturally, the Queen showed no sign of reacting to Rei's words.
Given that her body was currently being burned from within, there was no way she could muster any such response.
...Even before that, there was the question of how the Queen would even hear Rei's voice speaking inside her body.
If someone were inside Rei's own body talking, and he were asked whether he could hear them, his answer would naturally be no.
(Not that I think the Queen has the same kind of sensory organs as me, though.)
While pouring mana into the Flame Emperor's Crimson Armor with the image of wringing out every last drop, Rei pondered this with a mind that still had a slight bit of leeway.
Given his current situation, he shouldn't have had the composure to think about such things... and yet, strangely, Rei found he did.
The Queen could convey her intentions as a string of words, accompanied by a sound like fingernails scraping across a blackboard—a sensation that induced sheer revulsion.
Having experienced it many times already, Rei couldn't possibly believe her sensory organs were the same as his own.
Or perhaps... and this was a real stretch... maybe it wouldn't be strange if she could hear his voice speaking inside her body.
That said, he didn't think it would change the current situation even if she could.
Even if the Queen spoke directly into his mind, her words wouldn't make him ease up on his attacks.
"Hm?"
A sound slipped from Rei's mouth unexpectedly.
The reason was that the mass of flesh in his line of sight—the portion being burned by the crimson mana—appeared to have recovered, if only slightly.
For a moment, Rei thought it might be an illusion, but in the next instant, flesh swelled up around the area that had been reduced to ash, covering the wound.
"Is this... Regeneration Ability?"
It was neither a misperception nor anything of the sort. It was clearly the same Regeneration Ability the Queen had used at the very beginning, the same one the black-scaled Dragonias possessed... or perhaps an even more enhanced version.
"I see. So you stopped the vibration and switched back to Regeneration Ability."
As long as Rei was inside her body, the defensive enhancement from vibration was meaningless.
The Queen's ability enhanced her defensive power by vibrating her skin.
In other words, when it came to Rei inside her body, it served absolutely no purpose.
Also... the fact that Vihera and Set had headed for the surface, leaving Rei as the only one fighting the Queen, was likely a factor as well.
That was surely why she had chosen Regeneration Ability over the defensive power of vibration.
It was proof that she possessed not only the ability to birth Dragonias, but also a certain talent for combat.
"But... do you really think Regeneration Ability will be enough to save you!?"
Rei shouted, pouring even more mana into the Flame Emperor's Crimson Armor.
When it came to sheer mana capacity alone, Rei was unparalleled even in Elgin, but after maintaining the Flame Emperor's Crimson Armor for several hours, the amount of mana he had remaining was by no means plentiful.
Even so, for Rei right now, he could think of no other method to defeat the Queen and her powerful Regeneration Ability.
Or perhaps, if he took more time to think, he might have come up with something. But what Rei needed in his current situation was not deliberation, but haste.
Alternatively, he could have exited the Queen's body and fled from this Underground Space.
The countless Dragonias that had been in this Underground Space were now completely annihilated.
In other words, for the Dragonias race as a whole, they had unquestionably suffered a catastrophic loss.
Furthermore, while not everything was known, a significant portion of the Queen's abilities had been revealed.
Given that, there was also the option of retreating from the Underground Space, fully restoring his strength and mana, and then challenging the Queen again.
Of course, the Queen would not let him do such a thing so easily. She would likely order the Dragonias currently on the surface to attack Rei and his companions, and she would probably birth new Dragonias while they were recovering.
But looking at the overall picture, retreating once would undoubtedly be advantageous for Rei and his companions.
It was undoubtedly advantageous... but Rei had no such intention at all. He had resolved to settle things right here.
It was not for any particular reason.
Even so, if he had to give one, it was that Rei's intuition was telling him something dangerous would happen if he didn't defeat the Queen here and now.
That was why Rei had no intention of retreating. He would continue to activate the Flame Emperor's Crimson Armor even if it meant using up his remaining mana, strengthening the crimson mana that enveloped his body.
Then, as if responding to his will, the crimson mana covering his surroundings began to gain momentum at an accelerating rate.
The Queen's body instantly regenerated the areas burned away, but the regenerated flesh was seared once again in the next instant.
Both flame and regeneration fought to claim even a fraction more of each other's territory.
But... that balanced state was gradually—truly gradually—the crimson mana beginning to overpower the Regeneration Ability.
"Ugh..."
Naturally, Rei, who was pouring his already dwindling mana into the Flame Emperor's Crimson Armor, was not in any condition to be fine either.
Beads of sweat formed on his forehead like droplets.
Despite the Flame Emperor's Crimson Armor being active, the fact that the profuse sweat on Rei's face—and on his back, hidden beneath his clothes—was not evaporating made for a somewhat peculiar sight.
Rei, who was producing that very sight, had no leeway to worry about it, of course.
"Ugh... urgh..."
With every groan Rei uttered, the crimson mana shrouding his body grew more intense.
At first, the speed at which the crimson mana spread had been gradual, but by now, it had gained enough momentum to overwhelm the Queen's Regeneration Ability.
However, conducting such an overwhelming attack with his remaining meager mana naturally placed a heavy toll on Rei.
Looking at his expression—one he would normally never show—that much was immediately clear.
But... even driven into such a state, Rei never weakened the mana he was pouring in. On the contrary, he poured even more into the Flame Emperor's Crimson Armor.
Fueled by Rei's mana, the crimson mana grew ever more intense, burning through the Queen's body from the inside.
It had already burned away more than half of the Queen's body.
...Having more than half of her body burned from the inside and still being alive—the Queen's vitality was perhaps befitting of the being that had birthed countless Dragonias.
Even so, with half her body burned away, the Queen was in no condition to exert her original power.
If anything, like a levee breaking from a single crack, the balance between the Regeneration Ability and the crimson mana was clearly tilting in favor of the crimson mana.
"U... UOOOOOOOOOOOOOOOOOOOOOH!"
As the crimson mana's momentum became undeniable, Rei mustered his willpower and poured a clearly more powerful surge of mana into the Flame Emperor's Crimson Armor than before.
Whether Rei's mana had reached its limit or not, his vision blurred and his consciousness grew hazy, yet the mana continued to flow.
It was as if he was converting his very life force into mana and pouring it into the Flame Emperor's Crimson Armor. That powerful surge produced an even greater crimson mana... and that crossed the final line.
The crimson mana, having overwhelmed the Regeneration Ability, instantly engulfed the entire body of the Queen—that massive lump of flesh.
"GIIIIIIIIIIIIII!?"
Along with the scream, words surfaced in Rei's mind, accompanied by the sound of fingernails scraping across a blackboard.
Scorching heat... inside... void... spirit... life.
Such words drifted through Rei's mind, but whether it was fortunate or unfortunate, he was pouring everything into fueling the Flame Emperor's Crimson Armor with mana and using the crimson mana it produced to burn the Queen's body to ashes.
Indeed, the majority of the Queen's body—about eighty percent—had already been consumed by the crimson mana.
If anything, the fact that she was still alive despite being in such a state was what was truly abnormal.
Thinking about it rationally, it was unbelievable that anyone, even a Queen, could remain alive after having eighty percent of her body burned away.
That she could still survive was likely because her Regeneration Ability was barely managing to cling to her life.
By now, the majority of the Flame Serpents that Rei had released into the Queen's body through magic had vanished, overwhelmed by the crimson mana's momentum. ...No, it was more accurate to say they had been absorbed by the crimson mana.
Of course, since countless Flame Serpents had been deployed, naturally not all of them had disappeared.
Even now, they continued to writhe within the remaining twenty percent of the Queen's body, inflicting damage... but whether it was fortunate or unfortunate, for the Queen right now, the pain of her body being consumed by the crimson mana was so overpowering that the agony of the Flame Serpents rampaging inside her—while she certainly felt it—was faint enough to ignore by comparison.
"It's about... time you... DIIIIIIED!"
In his half-hazy consciousness, Rei nonetheless squeezed out the last of his mana, despite having already exhausted it, to put the final seal on this battle.
The mana, squeezed out along with his life force, swelled the crimson mana in an instant... and completely engulfed the Queen's body, which had barely managed to hold on at around eighty percent destruction through her Regeneration Ability.
"Gi... gii..."
A small scream, for one who had existed as the Queen of the Dragonias.
But that scream became her true death cry, and the moment her consciousness faded, the Queen's entire body was engulfed by the crimson mana Rei had unleashed.
"Haa, haa, haa, haa..."
Rei, who had been maintaining the Flame Emperor's Crimson Armor, must have sensed it instinctively.
Once he understood that the Queen's entire body had been ravaged and burned to ashes by the crimson mana, he finally released the armor he had kept activated for hours and collapsed onto the ground.
Ash from the Queen's burned body littered the area around him, but for Rei, who had exhausted his mana, he had no leeway to care about such things.
All Rei could do now was lie on the ground and continue drawing in ragged breaths.
Beyond that, he needed to recover even slightly from his current state of extreme mana depletion.
...That said, the best way to recover mana was to sleep.
But there was no way he could sleep in a place like this.
How much time had passed since Rei collapsed onto the ground?
It felt like a few seconds, or maybe thirty minutes, or perhaps even an hour depending on how he looked at it.
Still, after a certain amount of time had passed and his breathing finally settled, Rei stood up...
"Hm?"
He noticed something in his line of sight, about the same size as himself, like a giant black stone.
A stone different from the Magic Stones Rei was familiar with.
"Is this... the core?"
It was likely something like a core that had been somewhere inside the Queen's body.
Making that judgment, Rei used Death Scythe to cut through the black stone, just to be sure.
[Death Scythe has acquired the skill 'Terrain Manipulation Lv.5']
At the same time, those words flowed into his mind.
"...Huh? Why?"
Rei muttered in an absentminded voice so unlike what one would expect from someone in his exhausted state.
[Death Scythe]
'Corrosion Lv.5' 'Flying Slash Lv.5' 'Magic Shield Lv.1' 'Power Slash Lv.3' 'Wind Hand Lv.4' 'Terrain Manipulation Lv.5' new 'Pain Burst Lv.3' 'Penetrate Lv.3' 'Multi Slash Lv.3' 'Blizzard Slash Lv.1'
Terrain Manipulation: While the handle of Death Scythe is touching the ground, the terrain within a specific area centered on the user can be manipulated. At Level 2, within a 30m radius, the ground can be raised or lowered by about 50cm; at Level 3, within a 50m radius, by about 1m; at Level 4, within 70m, by about 150cm; at Level 5, within a 1km radius, by about 5m.