The Return of the Heavenly Demon
The return of Tenma, the nightmare of the Fan Empire who had died long ago. A passage to the underworld torn open in the night sky beneath the pouring moonlight. Even the descent of Thanatos, leader of the grim reapers who guided lost souls. Each event was monumental enough to be etched into myth and legend, yet the night slipped away beneath a heavy blanket of silence. No one had noticed a thing.
"Haaaaahm."
Only Kain, who had spent the entire night teaching Arina, possessed even a vague understanding of the flow. This had been a battle between dark mages. The activation of countless inner worlds made it impossible for him not to know what had transpired.
The gaze is gone.
Recognizing that the watchful eyes monitoring them had vanished, Kain yawned again and smacked his lips in irritation.
Did they wrap things up over there?
The thick aura of death that had swallowed the entire western sector carried a colossal weight reminiscent of the battles against the great nature of Yggdrasil. It could only mean an enormous number of undead had been summoned. Neither Pride nor Sloth specialized in necromancy, so the opponent must have been responsible.
They had managed to call forth undead impressive enough to catch even Kain's interest, yet Thanatos had crushed them in the blink of an eye the moment she appeared from the underworld.
Only natural.
Against an absolute being, victory through sheer numbers was meaningless. Excluding the four undead under Kain's command, no undead in this world could face an absolute being head-on.
Still, it took longer than I expected.
For someone like Thanatos to intervene personally, the resolution had been surprisingly slow. Kain rested his chin on his hand and lazily turned his head. There stood Arina, relentlessly firing mana spheres at the skeleton he had summoned.
Whoosh!
She barely dodged the skeleton's swinging arm. Her brownish-red hair whipped violently. The sweat pouring down her forehead and her ragged breathing spoke volumes about her exhaustion.
Bang! Clang!
Her spheres struck the skeleton's shoulder joints with perfect accuracy. Joints were the greatest weakness of skeleton-type undead. Unlike human bodies, they lacked protective joint capsules, muscles, or ligaments. They were merely assembled dolls with bones glued together by mana. While they offered superior freedom of movement compared to zombies, they fell far behind in durability.
Arina's current approach was therefore the most efficient strategy against a skeleton. If only this particular one hadn't been summoned by the Death King himself.
Clatter-clatter-clatter!
The skeleton ignored her attacks completely and charged. Her spheres slammed into its joints only to bounce off harmlessly. No matter how fragile skeletons were among the undead, a mere 3-star mage could never destroy one created by the Death King. This was the same one-man army that had slaughtered the zombie horde rampaging through the Grant Department Store single-handedly. Though it appeared to be a basic skeleton, its power rivaled that of a death knight summoned by a professional dark mage.
Thud!
Arina squeezed her eyes shut as the arm swung toward her with ferocious force. The white bone halted abruptly just above her forehead, delivering only a light tap using the flat of its length.
"Make the battle feel real. But if the little brat gets even a speck of a wound, you're dead."
The skeleton was faithfully carrying out Kain's orders from before the training began. It carefully inspected Arina's forehead, terrified it might have left the slightest scratch on the precious young lady. For some reason, it almost looked like cold sweat was pouring down its skull—impossible though that was for an undead.
Boing.
Ah, shit.
Seeing the tiny bump rising on Arina's head, the skeleton felt as if lightning had struck its mind. Its jaw hung open, limbs trembling. Desperately trying to compose itself, it blocked the line of sight between Kain and Arina with its hollow ribcage.
"I told you not to just hammer away at the parts that look weak."
Fortunately, the skeleton's efforts seemed to have worked. Kain, apparently unaware of the injury on Arina's forehead, spoke with eyes heavy with boredom.
"Besides, you can't destroy that skeleton through physical force anyway, little brat."
He had kept the physical strength intact but deliberately arranged the formulas composing the skeleton's ego in a sloppy manner. The absurd amount of mana forcibly boosted its performance, but the formula itself was only 3-star quality. If the little brat focused and attempted to hack it properly, it was a perfectly solvable problem.
"Easy for you to say."
Of course, that was only by Kain's standards. Hacking a skeleton infused with nearly 5-star mana or higher was anything but easy for a 3-star mage. The difficulty was comparable to hacking the final gate of a boat racing championship. And she wasn't standing still to focus solely on it—she had to solve the problem in the middle of combat. It was an incredibly grueling task.
Why can't she do it?
To Kain, it was simply difficult, not impossible, and therefore fully achievable. To Arina, its difficulty was exactly why she kept failing. That was the difference in their talent.
A genius could never teach an ordinary person. That principle was creating massive communication problems between them even now.
"Haaa."
Kain sighed deeply, unable to comprehend why Arina kept failing, and rose from his seat. His steps carried even more irritation than usual, since he hadn't slept while training her. The skeleton, meeting Kain's exhausted eyes behind those thick glasses, shook in its bones with primal terror.
I told you not to inflict even a speck of damage on the little brat's body.
The ominous purple aura flickering in those black eyes was telling the skeleton one thing: You're finished.
"So do it like this."
Claiming he would demonstrate once more, mana swirled around Kain. This was not the damp, unpleasant mana from another dimension he usually used for dark magic. Instead it felt clean and pure, like the mana of the great nature itself. After spending so long deliberately wasting mana, directly filtering it from the star felt strangely awkward.
Bang!
Despite that awkwardness, the flow of mana unfolding above his hand was incredibly natural and elegant. A mana sphere shot toward the skeleton just as Arina had done. It flew past the skeleton's upper body and struck something invisible in the empty air.
Clatter-clatter-clatter-clack!
The skeleton collapsed on the spot, clutching its entire body. Pain throbbed deep in its bones. Instead of screaming, it clacked its teeth loudly and stared at its master with desperate, pleading eyes.
"Like this."
But Kain's indifferent gaze held not a trace of pity. Bang! Bang! Bang! Bang! The mana spheres he fired created a rhythm game that rained down on the skeleton. Fireworks of explosions burst around it as the skeleton performed a frantic bone dance, screaming with its entire body.
Sssssss.
Unable to endure even a minute, the skeleton disintegrated into dust. Its final expression held no fear of death—only the pure joy of liberation from its suffering.
Having disposed of the 194th skeleton that had injured Arina tonight, Kain turned to her.
"Got it?"
"......"
Watching her uncle ask if she understood now, Arina felt a strange sense of déjà vu. He looked exactly like the perm-haired man from those old videos who would scribble out an incredible drawing and say, "See? It's easy, right? Anyone can follow along, can't they?"
"Alright, let's begin again."
As the 194th demonstration ended, another skeleton assembled before Kain. Looking at the 195th skeleton, which radiated despair at being dragged back to hell after its brief moment of freedom, Arina's eyes burned with determination. This time, I will succeed.
Still, she's growing remarkably fast.
Kain chuckled softly at the sight. It didn't meet his standards yet, but the little brat's growth rate was certainly quick. As expected of someone who learned magic with her body rather than her head. Even while taking hit after hit from the skeleton, she was steadily progressing through the steps on instinct and grasping the technique.
At this rate, it might be tight before the match starts today.
The desperate battle between Arina and the skeleton resumed, with only the skeleton's life truly on the line. Kain looked away and turned toward the hotel window visible beyond the simple sub-dimension.
Should I text that princess to say I'll be late?
The long darkness was lifting. Beyond the horizon, the sun rose, pouring light into the once pitch-black world. Seeing dawn break, Kain pulled out his smartphone to check the remaining time and message Marily.
"Hmm."
The report stated that although they had called Thanatos, the opponent had gotten away. Whether that opponent was the Heavenly Demon or something else held no interest for Kain. The only detail that caught his attention was that Thanatos had let a single small fry escape.
They called her the daughter of the King of the Underworld, so I had some expectations, but she's less useful than I thought.
Because of that, things would likely become more troublesome than anticipated. His foresight-like insight, sharpened by overwhelming power, allowed him to predict the coming events. Kain's brow furrowed slightly.
"Well, does it matter?"
No matter what happened, he could simply resolve it. In one sense it was negligence and complacency. At the same time, for Kain it was perfectly natural. Since awakening his ebon in that graveyard and returning home late only to be caught by his sister over the broken smartphone, he had never once felt a true crisis in his life. Not even when provoked by Tugwi or when clashing directly with the Empress.
When something happened, he could simply deal with it at the time. He possessed more than enough power to do so.
"......"
Thinking that, Kain slipped the smartphone—which had finally died—into his pocket. When he raised his head again, the confrontation had lasted quite a while. Perhaps the skeleton's desperate determination not to injure Arina at all had kept it going.
But that lasted only a moment. The instant Kain looked over, the skeleton's bony index finger swept past, severing several strands of Arina's hair.
The skeleton froze in place as if time itself had stopped. Trembling, its creaking joints turned so it could meet Kain's eyes.
"......"
Kain quietly raised his right hand toward the skeleton. He drew his thumb across his own throat in a slow, deliberate line and mouthed the words.
You're dead soon.
While the morning sun rose outside, the death king's verdict plunged the skeleton's future into utter darkness.