The battle unfolding on that battlefield was supposed to follow a simple plan: exploit the opening created when the monsters came to their senses and began fighting among themselves, then prioritize killing any that tried to flee the chaos.
But the Dark Elves' strategy fell apart almost immediately.
Several Dark Elves had charged headlong into the monster horde right from the start.
Whether they were hungry for glory or simply couldn't stomach the sheer number of monsters before them—regardless, a handful of Dark Elves plunged into the throng. The monsters, having only just snapped out of their frenzy, were still confused even if only for a few seconds, and couldn't mount a proper response.
As a result, the Dark Elves who charged in first caught the monsters completely off guard and managed to cut down a respectable number of them.
They succeeded—but when their comrades started falling, the monsters naturally turned their hostility toward the ones responsible.
The monsters nearest the Dark Elves abandoned their infighting and focused their attacks entirely on them.
Of course, not every monster that had regained its senses turned on the Dark Elves. At the edges of the horde, monsters were still tearing into each other as a matter of course.
Even so, the vast majority shifted their attention toward the Dark Elves.
It would have been manageable while the monsters were still fighting among themselves, but being swarmed all at once made resistance nearly impossible.
"Damn it, what were they thinking pulling a stunt like that! Once this battle's over, I'm going to thrash them!"
"You're right. We'll need to give them a proper piece of our minds once this is done. So don't you go dying in a place like this, alright?"
A Dark Elf Guard shouted bitterly as he drew his bowstring taut, his words carrying both fury and genuine concern for his fellow settlers. Beside him, another Dark Elf Guard who had been loosing arrows shouted back in agreement.
The battle pressed on even as they nodded at each other—but they were simply outnumbered. No matter how you looked at it, the side with greater numbers held the advantage.
As things stood, there was no way the Dark Elves could hold out against the overwhelming horde.
To make matters worse, even the monsters that had initially been fighting each other began to break off as they noticed the surrounding creatures surging in one direction, and more and more of them joined the charge.
The number of monsters the Dark Elves had to fight kept growing, and they were gradually pushed back.
Even those who had first charged into the horde had since retreated to the side of the Protective Barrier, no longer able to withstand the surrounding monsters.
For the time being, those Dark Elves got off with nothing more than a light reprimand—but only because they were still in the middle of combat.
Once this battle concluded safely, there was no doubt they would be disciplined.
No—if discipline was all they faced, they'd be getting off lightly. At worst, there was no denying the possibility that brutal practical training under Optis awaited them.
Should that come to pass, there was no question that the worst possible outcome awaited the Dark Elf men who had gone on their reckless rampage.
But perhaps it was a silver lining in the midst of misfortune, because those very same reckless fools couldn't spare a thought for such consequences right now.
They had their hands full dealing with the horde of monsters charging straight at them.
With the battle unfolding under those conditions, the Dark Elves naturally began to lose ground.
Even so, the fact that they felt no absolute despair was undoubtedly because the Protective Barrier stood right behind them.
If they were truly thrust into a life-or-death crisis, they only needed to retreat inside it.
Once inside, the monsters wouldn't be able to touch them.
The despair they had felt when the Protective Barrier had temporarily vanished had been immense for the Dark Elves.
It was possible that very despair had been what drove some of them to charge into the monster horde in the first place.
Compared to that hopelessness, they now had an absolute safe zone at their backs, so the Dark Elves didn't feel nearly as much dread as one might expect.
Of course, once they retreated inside the Protective Barrier, the monsters would likely attack it in an attempt to break through.
If that happened, venturing back outside would become difficult.
Having a safe zone behind them was one thing, but the Dark Elves' sentiment was that they didn't want to rely on it if they could help it.
Naturally, that included the desire not to burden the World Tree by letting the Protective Barrier take unnecessary attacks.
And as they were being pushed back but still somehow holding their ground, one of the Dark Elves spotted a figure approaching.
It was someone wearing a robe with the hood pulled up, but even so, the Dark Elf Guard who spotted the figure immediately understood who it was.
Because that figure was carrying a scythe larger than his own height.
Among everyone currently in the settlement, there was only one person who wielded such a weapon.
Only Rei, who had come to treat the World Tree.
The instant they saw him, one of the Dark Elves shouted.
"It's Rei! Rei has come!"
The best possible reinforcement had arrived in their moment of greatest need.
The moment that thought crossed their minds, it happened.
A portion of the monsters swarming the Dark Elves suddenly had their bodies sliced apart.
Setting aside the area of effect, the power itself wasn't particularly overwhelming.
Even so, among the low-rank, small-bodied monsters like Goblins, some had their heads severed outright by the ultrasound, and a sudden crop of monster corpses littered the ground.
The monsters that were wounded but survived, as well as those outside the effective range of the ultrasound, couldn't comprehend what had just happened.
It was sudden—truly sudden, with no warning whatsoever—that multiple monsters were slain and injured, so their bewilderment was only natural.
If they had been paying a little more attention to their surroundings, they might have noticed that Set and the Giant Cicada, battling in the sky, had been gradually drawing closer.
But unfortunately, neither the monsters attacking the Dark Elves nor the Dark Elves desperately fending off those attacks had anyone with enough composure to spare a glance at the battle happening overhead.
Set had wanted to fight in a location away from the settlement, but over the course of battling the Giant Cicada, it had naturally drifted back toward it—and now ended up causing collateral damage on the ground.
The only silver lining was that the casualties were limited to the monsters.
If the Giant Cicada's strike had also inflicted casualties on the Dark Elves, this battlefield would have instantly tilted in the monsters' favor.
And the monsters' misfortune didn't end there.
"Uoooooooooh!"
With that battle cry, Rei plunged into the midst of the monster horde, swinging the enormous Death Scythe—larger than his own height—to his heart's content.
Spinning as he moved, he severed the torsos of several Orcs, and the pommel crushed a Goblin's skull. A single swing of the shaft sent a cluster of Cobolts flying all at once.
In terms of charging into the monster horde, it was the same action the Dark Elves had taken at the very beginning of this battle.
But what was decisively different was, without question, their respective abilities.
Whereas the Dark Elves had some experience with hunting but almost none with large-scale combat, Rei had overcome countless major battles and was, above all else, the adventurer with the alias of Crimson.
What several Dark Elves had together failed to achieve before being overwhelmed by numbers, Rei was doing alone.
Monsters had their bodies severed one after another, collapsing to the ground, and the surrounding area became so littered with flesh, blood, entrails, and bones that there was nowhere left to step.
If someone who had just become an adventurer had been present, they would have slipped on the blood and viscera and tumbled to the ground.
Amidst all that, Rei swung Death Scythe while carefully choosing his footwork to step only on ground that was still safe to tread, and when he leaped to a spot where there was absolutely nowhere to step, he used the Sleipnir boots to kick off the air.
With such a flashy display, Set, battling the Giant Cicada overhead, naturally noticed Rei's presence.
Set, which had been locked in a state practically amounting to a stalemate, seized the opportunity and decided to pick Rei up.
However, it couldn't simply abandon the Giant Cicada as it was—it needed to stop the creature's movements, even if only temporarily.
Against the Giant Cicada, which had been empowered by absorbing Rei's magic power, pulling that off was no easy feat.
The option Set chose was to make the Giant Cicada paranoid.
"Grrrrrrl!"
The first move was Magic Eye of Shock—one of the fastest strikes in Set's arsenal.
The power itself was almost negligible, and Set understood that against an opponent like the Giant Cicada, the attack's potency would be minimal.
But even so, it succeeded in diverting the Giant Cicada's attention away from Set, if only for an instant.
"Gigigigigi!"
Set's calculation paid off. Struck by the shock without any warning, the Giant Cicada let out a cry of irritation, unable to comprehend what had happened.
Magic Eye of Shock was weak in power, but for the Giant Cicada, that itself became a source of frustration.
It was as if it were being toyed with—such humiliation.
Being a monster, the Giant Cicada had almost no facial expression to speak of, but its irritation still manifested in its voice.
The thought that the shock had been caused by anything other than Set never crossed the Giant Cicada's mind.
And as if it had been waiting for the Giant Cicada to steady itself with its four wings and turn back toward Set, what came next was Crystal Breath unleashed from Set's mouth.
Having intercepted Set's Fire Breath countless times with ultrasound, the Giant Cicada attempted to deal with this attack the same way—and in the next instant, though it didn't show on its face, it was stunned.
The breath it thought it had intercepted with ultrasound instantly transformed into tiny crystals that rained down upon the Giant Cicada.
The crystals themselves weren't particularly large, no bigger than a fingertip.
Even so, they carried enough force to temporarily seal the Giant Cicada's eyes...
"Gigigigigigi!"
It annihilated every crystal obstructing its vision with another burst of ultrasound, then immediately followed up with a shockwave.
Having blinded the Giant Cicada with Crystal Breath, Set intended to catch it off guard—and then catch it off guard once more.
The ultrasound fired with that intent slashed through and pierced nothing but empty air.
"Gigi?"
The Giant Cicada let out a puzzled cry. Set, which until moments ago had shown no sign of leaving its side and had been repeating ineffective attacks, was nowhere to be seen.
Given how persistent it had been, the Giant Cicada instinctively sensed that it hadn't simply blinded it and fled, and scanned its surroundings.
But Set was nowhere to be found.
That, in turn, bred paranoia within the Giant Cicada.
It couldn't believe Set had fled. It had to be waiting for an opening somewhere.
Given that, Set had to be nearby. If it moved carelessly, it would be struck by Set's attack... driven by that thought, the Giant Cicada couldn't bring itself to move.
If it had been any of the attacks Set had used so far, there would have been no problem at all. But even so, the Giant Cicada instinctively understood that Set was not an opponent to be taken lightly.
That might have been an effect of the Giant Cicada holding Rei's magic power, but regardless of the reason, Set was absolutely not an existence that could be dismissed as a weakling.
And so it waited for Set to make its move—a wait that would bring about a once-in-a-lifetime opportunity.
Rei, watching the battle from the ground, sensed that something was approaching him, even though he couldn't see it.
There was no way Rei could mistake what it was.
It was his partner, born from his own magic power.
And he also understood that it was invisible, and how and why it had become so.
(Optical Camouflage!)
Even as he anticipated the skill of the approaching Set, Rei swung Death Scythe.
An Orc that tried to block Death Scythe's attack with a club had, in the next instant, both itself and its club severed by the blade of Death Scythe, now infused with magic power.
(Optical Camouflage is a skill that could be called Set's trump card at present. One that can only be used once per battle—that kind of skill.)
To be precise, it could be used again once thirty minutes had passed since the previous activation, but unless it was an exceptionally large-scale battle, combat rarely lasted more than thirty minutes.
...Though it was true that over thirty minutes had already passed since the battle between Set and the Giant Cicada had begun.
Set had judged that this was the moment it needed that skill.
If it used Optical Camouflage to pull the Giant Cicada into close combat—Set's specialty—it might have been able to manage something.
But that would only work once, and if that single strike failed, picking Rei up would become difficult.
If so, the best course of action at this very moment was to pick Rei up.
So it judged—and then the now-invisible Set plunged into the horde of monsters where Rei was wreaking havoc.
Set descended and crashed into them while still invisible, and the impact was considerable. Goblins, Cobolts, and Orcs were sent flying one after another.
Then, still invisible, it headed straight for Rei.
"Grrrrrrrl!"
Set released its Optical Camouflage, revealing its form.
The monsters faltered at the sudden appearance of a Gryphon, but Rei, swinging Death Scythe, closed the distance to Set...
"Set!"
"Grrrrrrrl!"
Leaping onto the back of Set, which had arrived without scarcely slowing down—and taking the opportunity to slash through the monsters with one more swing of Death Scythe—the two of them, one person and one beast, soared up into the sky.