Transparent tentacles stretched from the sea toward Set.
Set dodged them while flapping its wings.
As Set tilted its body, Rei swung the Death Scythe he held and severed those tentacles...
"Tch!"
Sensing killing intent from behind, Rei reflexively swung the Death Scythe.
However, at the point where Rei swung, there appeared to be nothing at first glance.
...Even so, a solid sensation of having cut through something remained in Rei's hand gripping the Death Scythe.
What it was became clear when Set flapped its wings and pulled up toward the sky.
As if seeping out of thin air, the same type of tentacle that Rei had first cut revealed itself.
Its tip had been severed by the Death Scythe.
The day after he had fallen asleep leaning against Set... Rei was out at sea fishing just as he had been doing before.
He had even managed to catch a rather massive—giant tuna, like the kind he had seen on TV back in Japan—using a harpoon made in Emosion. But as he was searching for fish like that, he was suddenly attacked by a monster.
It only attacked by extending tentacles from within the sea, but their numbers and... above all, the fact that it could turn several of those tentacles transparent and control them were the real problems.
Since the tentacles had limited reach, flying higher would have prevented any attacks, and the monster would likely have given up and left... but for Rei, letting the monster currently attacking them escape was not an option at all.
That was because the monster currently attacking them possessed the ability to turn its tentacles transparent.
(Probably... no, likely—surely, if I have Set absorb this monster's Magic Stone, the Optical Camouflage skill should level up. Missing this opportunity is absolutely not an option.)
The reason Rei held what could only be called a firm resolve was that monsters with abilities like becoming transparent were not very numerous, and above all, Set's current Optical Camouflage level was four.
Since reaching level five would strengthen that skill dramatically at once, letting such a perfect opportunity slip by here was an unthinkable choice for Rei.
That was exactly why, even as tentacles endlessly attacked from the sea, he did not flee the area and instead kept the monster engaged.
Granted, the number of tentacles extending from the sea completely exceeded Rei's expectations, to the point where it felt meaningless no matter how many he severed.
(I can't just keep cutting only the tentacles like this... It almost feels like the tentacles are infinite, and even if they're finite, if the number drops too much, the monster might flee.)
Naturally, Rei had no intention of letting the monster escape, but if it dove deep into the sea and fled, pursuing it would become difficult.
That was why he needed to keep its attention and prevent it from getting away.
"Set."
"Gurururuu!"
At Rei's words, Set immediately responded and descended near the sea surface.
As it did, the monster in the sea apparently sensed this right away and extended its tentacles.
The number of tentacles was one, two, three, four... no, it quickly became more than could be counted.
On top of that, the extending tentacles were only those within the visible range.
Among them were undoubtedly some tentacles that had turned transparent—a characteristic of this monster.
(When there are many visible tentacles, I naturally need to focus my awareness on those... Tch, this is extremely troublesome. If I cut too many tentacles... no, given these numbers, would it be fine?)
He thought that for just a moment, but he still did not want to sever too many tentacles, make the monster sense danger, and cause it to flee.
Given that, even with the massive number of tentacles, he needed to avoid attacks as much as possible while somehow landing a fatal blow on the main body... that was what he had to do.
(But the problem is how to land a hit on an enemy inside the sea... I suppose.)
Since coming to this sea, Rei had experienced battles with various fish and monsters, but there was a major difference between those battles and the current situation.
That was the fact that the monster currently attacking Rei and the others was deep within the sea.
Until now, they had been able to clearly confirm its appearance from the surface, and even when it dove deep, they could faintly make out its silhouette.
But... the monster currently attacking Rei and Set was attacking from a depth so great that its form could not be seen from above the sea.
That was why a careless attack, if it failed to deal a fatal blow in a single strike, would likely allow the enemy to escape. He couldn't afford to strike carelessly.
(First, I need to clearly confirm the enemy's form... It'll take time, but it can't be helped. Right now, this is the only method I can think of.)
While dodging the tentacle attacks coming at him, Rei called out to Set beneath him.
Basically, Set could understand most things if Rei simply called its name, but in situations like this, he needed to explain things clearly.
Since this required a somewhat complex action—compared to giving instructions just by calling its name—that was only natural.
"Guuru!?"
Amidst many... sometimes nearly ten tentacles trying to grab Set and Rei... and drag them into the sea, Set flapped its wings, dodged them, and responded to Rei's call.
If Rei gave the order to attack, Set would immediately strike the tentacles stretching out around them.
The tentacles themselves were neither particularly hard nor highly flexible.
A single flash of Rei's Death Scythe would do it, of course, but even a strike from Set's front leg could easily destroy them.
The reason it didn't was because Rei had given orders to avoid giving the monster a sense of danger.
When things got truly dangerous, Rei would use the Death Scythe to intercept, but that was only for dire situations.
...If Set's body length had not grown to exceed three meters... if it had been, to put it in extreme terms, only about as large as Ielo, they wouldn't have needed to be this desperate.
Of course, if Set were about the same size as Ielo, it wouldn't have been able to carry Rei on its back in the first place.
At any rate, Set's large body made it extremely difficult to keep dodging the tentacles.
That it somehow managed to keep dodging anyway probably spoke to Set's greatness.
But such a situation could not continue forever.
At this rate, it was only a matter of time before Set's body was caught by the tentacles.
If it were only a few, given Set's physical abilities, it could tear them apart effortlessly, but...
"Avoid the enemy's attacks and gradually head toward the shallows! Right now I can't see the enemy's form in the sea, but once we reach a shallow area, we should be able to see it!"
"Gururu? ...Gurururuu!"
As if understanding Rei's words, Set gave a cry of acknowledgment, dodged the tentacle attacks, and flew toward the shore.
However, since completely shaking off the tentacle attacks would make the monster likely to give up, the movement was kept quite slow.
"Sorry, Set. Alright... I'll put in some effort too."
To make it easier for Set to move and to deal with the attacking tentacles, Rei stored the Death Scythe in the Misty Ring and instead took out a spear.
That spear was not the Twilight Spear that Rei normally used... but rather a spear with a chipped tip, one he used as a disposable throwing weapon.
It was a spear chosen for the purpose of not cutting the tentacles with its blade, but instead striking them with its shaft to deflect the enemy's attacks... a spear that was originally a discarded item.
But while avoiding cutting the tentacles and keeping the monster from becoming alert, he still needed to defend against the attacks.
For that purpose, the discarded spear Rei had taken out was actually more suitable.
"Ah."
Of course, perhaps the tentacles were more fragile than Rei expected, or perhaps the force of his swing was sharper than anticipated... there were times when he ended up tearing the tentacles apart with the impact rather than cutting them.
Still, after swinging the spear once or twice, he was able to grasp the right amount of force needed to deflect the tentacles without destroying them.
Having grown somewhat accustomed to handling that spear—accurately speaking, in the sense of being able to swing it without tearing the tentacles apart—Rei wove his way through the tentacles alongside Set, drawing closer to the shore.
The monster in the sea, perhaps irritated at being toyed with by Rei and Set's actions, eventually increased the number of tentacles extending from the sea even further.
Amidst tentacles stretching everywhere—including visible tentacles and ones that had turned transparent—Set flapped its wings and slipped through them.
If someone who knew nothing saw Set right now, it wouldn't be strange to describe it as swimming through the sky.
After swimming through that sea of tentacles toward the shore for several minutes...
Had it been flying at its normal speed, Set would have reached the shore in perhaps ten seconds, give or take.
But doing so would have without fail caused the monster to give up attacking Set and flee.
To prevent that, it was necessary to adjust Set's flying speed.
That is to say, quite slowly.
The effort of flying while adjusting speed paid off; the monster in the sea followed toward the shore without giving up on Set.
(I've heard that there are sea creatures that can't survive at certain depths... fortunately, this monster doesn't seem to be one of them.)
What Rei recalled was a TV program he had watched back in Japan.
Fish that live in the deep sea can sometimes die from the difference in water pressure if they are suddenly brought up to the surface.
But fortunately, the monster currently in the sea showed no particular effects even as it approached the shore.
(Is it because it's a monster, or did it simply have that kind of nature... or is there a possibility that it's because we're in Elgin?)
Thinking such things, he kept his gaze fixed on the sea.
Granted, given that they were moving while swaying in all directions—front and back, left and right, up and down—normally it would have been impossible to focus and see clearly.
But that was only true for an ordinary person, and Rei was far from ordinary.
As a result, even atop the violently moving Set, he was able to properly observe the inside of the sea.
And when the water depth had become considerably shallow, Rei finally understood the enemy's true identity.
"I could guess from the tentacles, but... it really is a jellyfish! How troublesome!"
Swimming through the sea with movements uncharacteristic of a jellyfish, its semi-transparent body made it extremely difficult to spot.
Even so, it was precisely because of the shallow water and Rei's senses, which were far sharper than an ordinary person's, that he was able to firmly spot its form.
"But once I've found it, I won't let it escape. Set, just once, get close to the sea surface for me!"
While calling out to Set, Rei stored the spear he was holding in the Misty Ring and took out a wired harpoon.
At Rei's instruction, Set let out a cry as it approached the sea surface.
Naturally, approaching the sea surface meant being attacked by that many more tentacles...
"Gururururuu!"
The flames of Fire Breath spewed from Set's mouth burned away many of the tentacles that had emerged above the sea.
Of course, Fire Breath could only be spewed from Set's mouth... in other words, Set could only unleash Fire Breath in the direction it was facing.
Tentacles approaching from below, to the side, or from behind Set would remain unscathed.
But that was of no concern to Set whatsoever.
That was because it understood that the tentacles could never catch up to its own speed generated by flapping its wings.
And in fact, Set's prediction was correct; the tentacles could not catch up.
...Though the monster probably never expected that Set, which had until now been constantly fleeing, would suddenly charge right at it.
Atop Set's back, Rei floated a triumphant smile, harpoon in hand.
The result of having devoted so much effort to evasion up until now had thus led to letting the enemy's guard down.
Then, confirming the sea surface was drawing near, Rei firmly gripped the harpoon he held...
"Set!"
"Gururuu!"
At Rei's call, Set flapped its wings broadly and forcefully changed its direction of flight.
A sudden ascent, as if drawing the letter V.
And the moment it began ascending, the harpoon Rei released pierced straight through the jellyfish's body.
"Alright, it's still alive, but now we drag it to the shore just like this! Same as with that fish monster!"
With a smile at having struck down—though it was still alive—a monster whose Magic Stone likely held the possibility of obtaining the Optical Camouflage skill, Rei called out to Set happily.