Rei's party—Rei, Set, Elena, Marina, and Vihera, four people and one creature—walked away from the tent and continued for about thirty minutes.
They hadn't walked at an ordinary pace but at the speed of adventurers, and naturally, that pace was far swifter than that of people going about their daily lives in the city.
As a result, even thirty minutes of walking had put plenty of distance between them and the camp.
Of course, knights and soldiers were stationed in a perimeter around the area designated as the battlefield.
Considering that, if they kept walking, they might pass straight through the center of the battlefield and end up on the opposite side.
That was why Rei eventually decided they'd gone far enough. He stopped and spoke up.
"This should do. Is everyone ready?"
He drew Death Scythe and the Twilight Spear from his Misty Ring and called out to Elena and the others.
The rest of the group nodded, each holding their own weapon.
Seeing that everyone's combat preparations were complete, Rei next took a Paired Orb from his Misty Ring.
Naturally, this Paired Orb wasn't the one shared with Elena—it was the one linked to Grimm.
"Grimm, can you hear me? Grimm."
He activated the Paired Orb and called out, and after a moment, Grimm's figure appeared in the space that had previously shown nothing.
'It seems you are ready. Then, as promised, I shall use Rei's mana as a landmark to perform the teleportation. As I told you before, my role is strictly the teleportation itself. Even if you find yourselves in crisis, I will absolutely not intervene to help. Is that acceptable?'
Grimm asked as though making one final confirmation, and Rei nodded as if the answer were obvious.
"That's fine. It was a situation we couldn't do anything about without Grimm to begin with. Given that, I'll honor Grimm's requests as much as possible."
Of course, if it were a request that was flatly impossible to fulfill, that would be another matter entirely.
He kept those words to himself, thinking them only in his head.
That said, Grimm was an existence that had lived for a very long time—though, being Undead, he wasn't technically alive.
It wouldn't be strange for him to have a general understanding of what Rei was thinking.
The fact that he said nothing about it was perhaps a form of consideration from his elder.
'Then, I shall begin. Let me warn you—once I start, I cannot stop midway. Also, I do not know precisely what the entity I am pulling out actually looks like. It is possible that something so abhorrent it defies description may emerge. Is that acceptable?'
"You're being overkill. I'm already fully aware of all that."
'Hm. Then...'
With those words, the Paired Orb's image cut out.
For a moment, Rei wondered how Grimm would observe their battle without the Paired Orb—but then again, Grimm could see perfectly well even in the Underground Space where the tentacles dwelled.
Given that, Rei concluded there would be no issue monitoring them without the Paired Orb, and he stowed it in his Misty Ring.
Knowing a large-scale battle was about to take place here, it was a precaution against the Paired Orb being damaged by any stray strike.
"They're here."
At that exact moment, Vihera shouted.
The joy in her voice was unmistakable—she was thrilled at the prospect of fighting the tentacles.
When she had fought them in the Underground Space before, part of the problem was that she hadn't known what to expect from the tentacles. As a result, she'd ended up in danger and had to be saved by Rei.
That was why being able to fight the tentacles properly this time—her own power, cooperating with Rei and the others—was what made Vihera so genuinely happy.
"Well then, let's open with a full burst."
A rift in space tore open, and within it crawled static electricity—no, Purple Lightning worthy of the name. Watching it, Rei began chanting.
'O flame, manifest Destruction, one of your true forms, upon yourself. You are that which burns all to ash, erases, and annihilates. Bring forth great Destruction, and become the sacrifice for new rebirth.'
As he chanted, a single Fireball materialized at the tip of Death Scythe.
It wasn't like the Flame Magic Rei typically used, generating numerous Fireballs at once. This was truly just one.
But that single Fireball had Rei—who possessed tremendous magical power—pour an extraordinary amount of mana into it... and then the spell activated.
'Scorching Hellfire!'
The Fireball, obeying Rei's will, flew straight toward the spatial rift—the rift that Grimm had interfered with, forcibly connecting it to the space where the tentacles dwelled.
And then, as if timed perfectly—or perhaps Grimm had actually timed it—the rift opened wide, and the tentacle master instantly launched tentacles through the gap to counterattack whoever had summoned it to such a place.
But the moment the tentacles burst from the rift, Rei's Fireball struck them head-on, engulfing the surroundings in ferocious flames.
So ferocious that getting close would make it impossible to keep your eyes open. No—even Rei and his group at a considerable distance wouldn't have found it strange to feel a stinging heat from the blast of hot air.
Naturally, the snow that had accumulated on the ground evaporated in an instant.
"Water Spirits, please!"
The heat was so intense that Marina formed a protective membrane of water over the group using Water Spirit Magic.
This was no ordinary water membrane. Marina was undoubtedly top-class in the Kingdom of Mireana—no, in the entire world of Elgin—as a Spirit Magic practitioner, and the membrane she created reflected that skill.
Naturally, something like a Fireball cast by an ordinary mage would have been instantly nullified or even extinguished.
But the one who cast this magic was Rei.
Even though the membrane wasn't blocking the spell directly, the hot air alone was enough to make it gradually evaporate.
The tentacles caught by magic of such power naturally couldn't escape unscathed. Every tentacle that had emerged from the rift was burned away—no, incinerated.
"Ugh, w-wait, Rei. Isn't this overkill!?"
From within the water membrane, Vihera shouted without bothering to hide her displeasure.
For Vihera, she had probably wanted to land the first strike herself.
Her complaint was born from having that chance stolen by Rei.
Listening to Vihera's protests, Rei kept his gaze fixed on the scorched area and spoke.
"Overkill? Look."
His words carried a hint of exasperation.
The reason for that exasperation became immediately clear if you followed his gaze.
There, tentacles were burning one after another in the searing flames Rei had created.
...But only the tentacles.
The tentacle master was currently being dragged out of the spatial rift by Grimm, but the process wasn't yet complete. Against Rei's expectations, the creature was resisting Grimm's power.
(I figured Grimm would brush off that kind of resistance and force it through.)
That assumption was precisely why he had opened with this spell.
But in reality, while Rei's magic had succeeded in burning a great number of tentacles, the entity that could be called the main body was nearly unscathed.
"...Nearly unscathed, huh. Debatable whether that's something to celebrate."
Marina murmured in Vihera's place, though she shot a sidelong glance at Vihera, who was clearly pleased despite those words.
"Even if the main body is unscathed, burning that many of its tentacles is still significant, I'd say."
Elena murmured, holding Mirage as she calmly observed the enemy... then furrowed her elegant brows slightly.
"However, no matter how many tentacles Rei's magic burns, there seem to be plenty more to replace them."
She was right. Tentacles continued emerging from the spatial rift one wave after another, only to be consumed by the scorching flames.
With no sign of relenting, they kept pouring out—tentacles, tentacles, and more tentacles.
That said, Rei had already witnessed tentacles emerge in massive numbers back in the Underground Space.
When the tentacle master had taken damage from a thrown spear, it had released a huge swarm of tentacles through the rift, using them to form a shield—no, practically a makeshift barricade.
Several minutes passed in that state... and then, the scorching flames centered on the spatial rift rapidly began to lose their effect.
Watching the scene beyond the water membrane, Rei had a question.
He hadn't done anything to interfere—so why were the flames dying out so quickly?
The fire should have kept burning the tentacles for much longer. Why?
(Well, if I had to name the cause, there aren't many possibilities. Which means...)
The tentacles kept emerging from the rift and being burned, so something about them was probably extinguishing the flames.
(Probably the mucus secreted on the surface of those tentacles.)
The fire's intensity had diminished considerably, but this was still a spell loaded with a massive amount of Rei's mana.
Even so, it continued burning the tentacles that refused to stop emerging from the rift.
"Hey, they're using those tentacles to put out the fire over there. Do you think that's actually dealing damage to the enemy?"
The three women who heard Rei's question wore uncertain expressions.
The tentacles were indeed being continuously burned, and a substantial number had already been reduced to charcoal.
But the momentum of the tentacles pouring from the spatial rift showed no sign of weakening whatsoever.
It was as if, to the tentacle master, losing this many tentacles wasn't taxing in the slightest.
Seeing them come wave after wave, it was only natural for Rei to think so.
"Rest assured. I can't say exactly how much damage it's taking, but for that tentacle master, it's definitely feeling it. ...Though exactly how much, I couldn't say."
Marina spoke with the confidence of a guarantee, and almost simultaneously, the scorching flames around the spatial rift died out completely.
"I hope so... But from the looks of it, even if it is taking damage, who knows how much."
"I can at least tell it's nothing major. ...More importantly, if the flames are gone, it's finally our turn."
Elena responded to Rei's words, turning a gaze burning with battle intent toward the spatial rift.
The tentacles emerging from it burned one after another, but the instant they caught fire, they crumbled to charcoal or ash and vanished—leaving no remains on the ground.
That was a relief for Rei's group, given the major battle about to unfold here.
"That said, even if we attack, the tentacles are ultimately expendable to the enemy, right? In that case, wouldn't it be better to maintain this situation until Grimm pulls the tentacle master through entirely?"
At Marina's words, both Vihera—who had looked ready to charge forward at any moment—and Elena—who had been about to wield Mirage in whip form from long range—calmed down slightly.
"Thinking of it that way, should I keep hammering them with magic?"
"If it's spells less powerful than that opening strike, it could be effective in terms of whittling down the tentacles at least."
There was something slightly off about the expression "whittling down tentacles," but considering the spectacle before their eyes—the endless stream of tentacles pouring from the rift—even if the phrasing wasn't precise, it certainly captured the situation well enough.
Nodding at Marina's words, Rei spoke.
"Then I'll keep casting from here. Time it and drop the water membrane—no, just clear a gap in front of me."
He stated it as a given rather than asking whether she could manage it.
And there was no way Marina would say she couldn't.
"Leave it to me. You just use magic to your heart's content, Rei."
She said it with absolute certainty.
What followed was a relentless barrage—countless Fireballs, Flame Birds, and Flame Arrows screaming through the air, incinerating each wave of tentacles the moment they emerged from the rift.
The tentacles came without end, but the magical flames that devoured them instantly were a sight that could only be described as terrifying.
And then, roughly thirty minutes after Rei began his assault...
The tentacles pouring from the spatial rift stopped. Abruptly. Completely.
"Here it comes!"
With Rei's shout, Grimm's power forced the tentacle master out of the rift—and hurled it into their world.