"Ugh... this evil presence is stifling... To think there was a Demon capable of creating a barrier like this...!"
Jiriel muttered as he surveyed our surroundings.
A vast garden stretched out around us, filled with ordinary flowers I recognized well. Right next to us stood a tower so tall I had to crane my neck to see its peak.
"...Actually, this place looks just like the academy."
"A barrier of this nature is created by bleeding into physical space. It is much like how the Celestial Realm was constructed from sky and clouds."
I see. That made sense. The created space drew from the landscape of the real world.
"But it's quite a bit smaller than the Celestial Realm."
When I visited the Celestial Realm before, I couldn't find the end of it no matter how much I walked, but this space seemed only about as large as the academy grounds.
"That is only natural, Master Lloyd. No matter how powerful the Demon who created this barrier may be, it cannot compare to the Celestial Realm fashioned by the Chief Gods."
"I suppose so."
Regardless, with an area of this size, I could likely sense the entire layout with my Presence Detection. I immediately extended my mana, spreading it thin and wide throughout the space.
"...Found him."
This presence was undoubtedly Grimo's. It seemed he wasn't very far from here. First, I needed to make contact with him and get the full story—
"!"
Suddenly, something brushed against my Presence Detection. An abnormal amount of mana... I see, so this was the Demon in question. He appeared to have noticed my detection as well, as he came charging straight toward us.
"H-Here he comes!"
As Jiriel cried out, a black shadow slammed into the garden, bringing with it a tremendous blast of wind. Amidst the fluttering petals, the shadow slowly stood up.
He wore a jet-black tailcoat and white gloves, looking very much like a butler. However, his body possessed two heads, and both of them were dogs.
"Well, this is a surprise, Kero-su. How many centuries has it been since someone trespassed here without permission?"
"Quite so, Beru-su. And a human, no less. I wonder if they have made any progress over the last few hundred years?"
Kero-su and Beru-su—the two-headed dog-man addressed each other in a leisurely tone. Seeing this, Jiriel gulped.
"The Double-headed Watchdog, Cerobels...!"
"Do you know him, Jiriel?"
"Yes. It is the name of the butlers who have served a family of great nobles in the Demon World for generations. I had only ever heard of them in rumors, but..."
While Jiriel listed off those impressive titles, I was more interested in how those heads worked.
"Two heads... I wonder what the internal structure is like."
They seemed to have separate personalities; I wondered if they could both cast magic at the same time. If so, was Double Casting their default state?
Double Casting magic is difficult to replicate, and the backlash from a failed cast is severe, so research into it hasn't progressed much. I mostly used existing combinations, so a Cerobels who had lived like that for hundreds of years must be capable of something far more incredible. ...Hmm, this looks interesting.
"...That boy, I wonder what he finds so amusing, Kero-su?"
"There is no way a human could maintain their sanity upon laying eyes on us Demons. He must have lost his mind from fear, Belo-su."
"Oh, how pitiful. Rest easy, human. We have no interest in toying with humans for pleasure like those low-born sorts."
"Indeed, indeed. We are only here to do our job. Which is—"
The moment he spoke, Cerobels vanished. And then—
"—Simply to eliminate intruders in our capacity as watchdogs."
I heard both their voices simultaneously from right behind me. A split second later, a dull impact rang out. When I turned around, I saw that Cerobels's arms had shattered several layers of the barriers I always kept deployed.
"...Oh? This human's barrier is unexpectedly sturdy, Kero-su."
"He did make it all the way to the Hidden Side. This much is to be expected, Beru-su."
Oh, he's quite fast. Just before he disappeared, I caught the faint sound of a spell that seemed like Physical Strengthening. It was extremely high-speed Double Casting; the logic seemed the same as the Ancient Magic Grimo used, but it was much more refined. Since he's a High-ranking Demon, he might possess some kind of Bloodline Magic.
The effects were also far superior to what I usually used... Nice. I'd like to see his other spells too. I wanted to see his defensive magic first... but magic isn't very effective against Demons. I'd seen them take Supreme Magic in their base state without a scratch. ...Right, maybe I'll try that.
With that thought, I began kneading mana into my palm. The moment he saw it, Cerobels's expression changed.
Using Compressed Casting via a Spell Bundle, the high-density spell formula used the mana I'd gathered in my palm as fuel to manifest flames. The fire swirled, instantly becoming a massive orb of flame that brightly illuminated the area. It gradually condensed, changing shape until it took the form of a four-legged beast.
"Fire System Large-scale High Magic: 'Crimson Tiger Force'."
With a roar like a tiger's howl, the unleashed flames surged toward Cerobels. He attempted to dodge, but it was futile. The flames released by Crimson Tiger Force automatically tracked the target.
"Nu—!?"
The flaming tiger caught the frantically moving Cerobels with its claws and fangs, biting down deep. In that instant, it triggered a massive explosion.
"Hmm, Large-scale Magic really is too flashy."
I was protected by my own barrier, of course, but the heat turned the surrounding plants to ash, and the air grew so dry it scorched my throat with every breath. This is far too conspicuous; I can't really test this anywhere but a place like this.
"L-Large-scale Magic by himself... That should be impossible to activate without a ritual or an altar!?"
"Ah, normally it would be impossible without Diguardia."
The golem I created, Diguardia, possesses the functions of a magical altar, and by boarding it, a single person can handle Large-scale Magic. However, that usually required being inside it and connecting one's Magic Lines. But now, thanks to optimization through Military Magic, I've become able to extend my Magic Lines over great distances, allowing me to connect even with a Diguardia located far away. Therefore, I can use the altar anytime, anywhere, and thus handle Large-scale Magic like this.
"Gu, nununu..."
Cerobels emerged from the clearing black smoke with a groan. His eyes were wide with irritation, and he gritted his teeth as he tossed aside his tattered gloves.
"Waaaaah! To deal damage with magic to a High-ranking Demon with a high-level Magic Body! As expected, as expected of Master Lloyd!"
"No, the damage doesn't seem as bad as it looks."
Though his surface was soot-stained in places, his actual Magic Body was still perfectly fine. I'd held back quite a bit so as not to destroy this space, and he'd guarded with a Magic Barrier. The power was probably less than ten percent, but to mitigate Large-scale Magic to that extent—that's quite a good Magic Barrier. I wanted to observe it more, but... well, there will be plenty of opportunities.
Just as I was about to retake my combat stance—
"The hell is this weird space? It's like a barrier, but... it's a strange one."
Suddenly, a voice came from behind me.
"This is a Dimensional Wall. You truly are uneducated, my foolish younger brother. Regardless, why on earth is such a thing in a place like this...?"
It was Gazel and Noah. Come to think of it, poking a hole in the Dimensional Wall was fine, but I'd left it wide open. They must have found it and come inside.
"Oh, if it isn't Lloyd! And is that a Demon you're fighting!?"
"It is likely the Demon who generated the Dimensional Wall. Did it escape from a seal somewhere? We shall assist you as well, Lloyd-kun!"
Gazel and Noah ran forward in perfect sync.
"Foolish! What can humans hope to do against a Demon! You two, leave this to Master Lloyd and run!"
"No, wait, Jiriel."
I stopped Jiriel as he tried to hold them back.
"They must have some kind of plan. Let's watch for a bit."
"Mu, muu... If that is what you wish, Master Lloyd..."
Jiriel looked dissatisfied, but I felt a strange yet very powerful sensation from the brothers' mana. Could that be the Progenitor's Spell Formula I've been so dying to see? How exciting.
"Let's go, Scumbag Older Brother!"
"Keep up, foolish younger brother!"
With a synchronized shout, the two charged toward Cerobels.