The bottomless pit, the land Mother Earth had declared she would no longer support. A place where even an accidental slip meant experiencing an endless fall—a hell that truly existed in the mortal world.

Darkness so deep one could not see an inch ahead, hope impossibly distant, a future that only led farther from the sky. At the bottom, if a bottom even existed, things that had sunk without burial for over a thousand years lay congealed together, glaring up this way.

A dreadful, uncanny land, hundreds of years removed from peace and stability. Such was the bottomless pit. And yet...

'Why isn't anything going wrong?'

One who had experienced regression, the only traveler who climbed backward through time by way of death.

Amid the peace, Shei alone was gripped by unease.

'According to the undying one, something definitely happened here. The Instructor tried to kill someone, a Beast King howled, the undying one's flesh was cursed and scattered—an incident serious enough to bring down the bottomless pit.'

The future she had inhabited was a cesspool fed by dozens of sewers. Even if she plugged one, untreated sewage would burst out somewhere else and befoul the world.

Shei was alone, and there were far too many variables. Even a thousand hands would not have been enough to stop them all. Unable to withstand its shattered balance, the world had finally opened the floodgates to the apocalypse.

Sinister incidents offered themselves as harbingers of the terrible tragedies to come. Monsters appeared out of nowhere and devoured people; an entire village vanished without leaving a single corpse behind. Beast Kings howled at the coming apocalypse and rampaged like mad.

At the edge of the apocalypse, Shei had struggled to find its source rather than stop it.

Following its trail had brought her here, to the bottomless pit.

Within it, she had found the Progenitor, the King of Dogs, and the undying one, who would become the seeds of future calamity.

Yet contrary to her expectations, they were peaceful.

'It's not as if nothing has happened. But compared to what's coming later... things aren't that bad. Is it because my coming here changed the past entirely? Or is something enormous going to happen that changes all of this at once?'

Perched on the prison rooftop, Shei looked down into the yard.

On the monochrome concrete ground, a dark-blond girl stood facing a man in an instructor's uniform.

Azi kept twitching as though something was bothering her. Before her, the Instructor wore an unpleasant grin.

"Heh heh. Why didn't I think of this sooner?"

"Grrrrrr."

"Gahahahaha! Yes! I've finally found a way, Azi! You're no match for me now!"

Judging by his words alone, he might as well have been the mastermind behind it all, but Shei no longer let that attitude bother her. She had been fooled far too many times for that.

What the shouting Instructor pulled from inside his clothes was a thin disc made by hammering steel flat.

He raised it and rubbed beneath his nose.

"Ah, yes. This is what we call a flying disc. A broad, round plate designed with air resistance in mind! It stays airborne several times longer than a ball! Heh heh heh! With this, I don't have to worry about my shoulder anymore! One good throw could keep it flying for thirty seconds!"

"Grrrr! Woof! Woof!"

"All right, all right. Tch. So impatient. Can't even let me brag a little. Here, fetch!"

"Woof!"

He wound his arm back in a wide arc and threw the disc. The steel disc spun slowly as it sailed into the distance. Azi, who had been waiting all this time, brightened and chased after it.

Gliding through the wind, the disc did not come down easily. It rose gently and descended even more slowly. Catching up in an instant, Azi hopped beneath it, waiting for it to fall.

Meanwhile, the Instructor plopped down where he stood and laughed loudly.

"Heh heh heh. And that gives me plenty of time to recover! This is practically a semi-idle toy! Keeheehee! I'm not afraid of you anymore!"

"Woof!"

At that moment, Azi leaped into the air and snatched the disc in her mouth. Watching her, the Instructor's face went blank.

"Hey, hold on. Azi. Jumping to catch it is cheating. Let's keep this a fair, two-dimensional contest. And what kind of dog has a three-meter standing vertical jump? I told you to give me time to rest!"

"Woof!"

"No, ah."

But Azi brought the disc back in her mouth, and the Instructor sighed and got up.

Watching them made Shei feel stupid for being so tense. However fiercely she glared, the sight of Azi happily wagging her tail and the Instructor continuing to play with her despite his apparent annoyance left her with nothing but a weary sigh.

She wanted to sharpen her nerves, to hone the blade of her hostility.

Yet she could not even summon the will.

'If I had to pick someone here with enough influence to cause all that, the Instructor is the only one.'

Azi, with that innocent smile, hardly seemed likely to give such a savage howl. Nor did the composed Tyrkanzyaka seem likely to go mad and suddenly run wild.

At the same time, that man... the Instructor, whose name she still did not know, hardly seemed likely to do anything either.

'If only nothing would happen. If only someone could make me certain of that.'

Then she, too, could lay down all her burdens and enjoy a brief respite.

But the Regressor had seen the future. She knew that something tragic would happen in this bottomless pit.

That was why she could not relax. She had to stay alert. Even if everyone else let their guard down, she alone could not.

There could be no rest for someone who had seen that terrible future. Even this isolated pocket of peace inevitably felt like a portent of disaster.

'Now that I've come this far, I need to gain something from this run...'

Alone on the edge of the rooftop, she drew one knee up and quietly watched the disc flying below. Slowly growing larger and smaller with a dog trailing behind it, the disc seemed to embody peaceful everyday life. Rising and falling as nature intended.

As she sat there amid that uneasy peace...

"Shei. Could you spare me a moment?"

A calm voice addressed her. Recognizing its owner, Shei hastily stood.

A coffin of incense cedar, wreathed in dark-red energy. Progenitor Tyrkanzyaka sat demurely atop it, holding a pitch-black parasol. When Shei turned to face her, Tyrkanzyaka alighted lightly on the rooftop.

"Tyrkanzyaka! Uh, long... time... no see? Where's that guy you keep around?"

"Finlay? I left him alone for a while. Pay him no mind."

A peculiar chill laced her seemingly indifferent tone. Shei swallowed. She needed to build a good relationship with the Progenitor for the future's sake, but why was she so strangely cold every time they met?

Feeling even more conflicted, Shei spoke cautiously.

"What brings you here? You don't usually come looking for me. No, I don't mean I'm upset about it. I was just, um, stating a fact... I'm only asking because I'm curious!"

Tyrkanzyaka cut Shei's rambling short and answered.

"Did you not tell me the other day that unique magic is more powerful than standard-issue magic? You boasted at length that unique magic, which embodies one's own mystery, is overwhelmingly superior to standard-issue magic that anyone can use."

"Yeah. I did say that."

"And you said your magic recreates the power of the sky. A mystery you wield through the power of that sword."

"Y-yeah."

"Then..."

Tyrkanzyaka released her parasol. The darkness crumbled away in an instant, revealing her pale figure beneath the light.

"You should be able to wield lightning as well. Am I correct?"

"I can, but why?"

"Use it on me."

Even Shei, who had been through everything, could only question those words.

"What? Why?"

"Could you simply do it without asking why?"

"I need to know what you're trying to do before I can help."

"... You have a point."

After muttering something to herself, Tyrkanzyaka readily explained.

"Do you remember when the earthfolk rose again?"

"Oh. Back then."

When Rash, the undying one, had first opened his eyes. Yes, the Instructor had delivered an electric shock to his chest, and the undying one had sat up.

"Yes. He restarted his heart with an electric shock. If even an undying earthfolk can do so, then surely I can as well."

"You want to make your heart beat again with electricity?"

Shei understood what Tyrkanzyaka was asking.

Just as electricity applied to the earthfolk's chest had made his heart beat, she wanted her own heart brought back to life.

It must be a desperate wish she had cherished for a long time inside her coffin. Shei knew that, but she could only look troubled.

"I'm sorry to say this, but that would be difficult with my power. Magic is founded on the manifestation of the mental image within a being. One magic, one world. Using it to invade and alter someone else's body is extremely difficult, and it shouldn't be done. It violates another person's dignity."

"But the earthfolk rose through the magic he used, did he not?"

"That was level 0, phenomenon-grade magic. It's extremely minor magic that only produces phenomena that already exist in the world. If the true essence of magic is changing the world, then level 0 magic is the art furthest removed from it. It can only revive someone who can already be revived."

Shei calmly finished her explanation, thinking that this should suffice as a polite refusal.

However wondrous magic might seem, its limits were clear. She hoped Tyrkanzyaka would not think she was refusing because she could not be bothered.

Unfortunately, the vampire was accustomed to such expressions. This was practically a blunt declaration.

"I know that as well. It must be all but impossible for my heart to beat again. I understand your reluctance to undertake something futile."

Afraid of being misunderstood, the Regressor hurriedly protested.

"N-no! I'm just worried it might hurt you!"

"Pain is of little concern. In my twelve hundred years of life, I have suffered every manner of pain... Though, of course, even that may not have been true pain."

With a self-mocking smile, Tyrkanzyaka approached Shei. She spread her arms and let them hang limply, as though declaring she would not resist.

"Please, Shei. Even if your magic brings nothing but pain, I shall gladly accept it if that pain is real. I do not believe this will revive my heart, either. I merely wish to feel."

Tyrkanzyaka was adamant, and Shei was at a loss.

She could not understand why Tyrkanzyaka specifically wanted to be struck by lightning, but she could hardly refuse such an earnest plea. Tyrkanzyaka would be the one enduring the pain, after all.

It was not even dangerous for her. Shei's magic was powerful, but only by a magic swordsman's standards. If that degree of power could endanger Tyrkanzyaka, she would never have survived this long.

"Ugh. I don't see any major problems, but..."

After much deliberation, Shei drew Sky Cherry Blossom from where she had left it floating overhead.

Though Shei wielded Sky Cherry Blossom like a sword, its true nature was extremely compressed space. That was why it had neither weight nor thickness. Forcing its way through space and cutting it apart, Sky Cherry Blossom was sharper than any sword in the world.

Shei flicked it through the air, infusing it with mana as she explained.

"My magic uses Sky Cherry Blossom as a medium. Since the medium is so powerful, it has the drawback of giving my magic a distinct sky attribute. But the sky itself encompasses countless phenomena, so with enough preparation, I can recreate all of them."

Wind flowed from Sky Cherry Blossom. The compressed space unfurled, gradually expanding its presence. Space swelled abruptly. Air chilled by its own expansion brushed against skin, and the water vapor shivering in the cold seized the opportunity to cling to that warmth.

A vampire's skin was an exception, of course. Their bodies were as cold as the expanded air.

"Wind, clouds, rain, and dew; frost, snow, thunder, and lightning. Wind makes clouds, clouds bring rain, and dew rises from the earth to bead on the grass. Ordinary everyday life, steeped in tiny droplets too small to see."

And then...

The air stirred ominously.

The wind trembled as though gripped by fear. Sensing a portent of ill fortune, space scattered in a frenzy.

Within it, Shei's hair began to stir. Not from the wind, but in an electric, regular rhythm like a heartbeat.

Gripping Sky Cherry Blossom tightly, Shei released her mana. Spreading from her entire body, it surged into the air and gathered in one place.

Its shape resembled a cloud. In the bottomless pit, where no sky existed, a lone cloud hung like a still-life painting.

"Frost, snowflakes, and thunderbolts. Those are warped aberrations. When droplets neglect their duty as messengers, the conflict between earth and sky reaches its extreme, and twisted things fall. What I shall summon is a roar of wrath. The sky's majestic rebuke to the world."

Lightning flashed within the pitch-black storm cloud flowing from Sky Cherry Blossom. Bearing immense power, the cloud drifted slowly over Tyrkanzyaka's head. As her clothes and hair rose in response to that ominous portent, Tyrkanzyaka merely stared ahead without a word.

"Tell me if it hurts. I'll stop."

Tyrkanzyaka did not answer. Shei heaved a deep sigh and inscribed her magic upon the world.

"Heavenly Sword Art, Thunderbird."

An instant later, lightning flared.