The Heavenly Demon Sword

Ooh-hoo!

Some time later.

Under Hilda's ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠faintly wary gaze, Lucy and I were led through the streets until we came to a stop before a sign that read Ironheart Weapons Shop.

"We're here. Though, as I mentioned earlier, it's a little messy inside… ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠you're sure that's all right?"

"Doesn't matter. Let's go in."

"Wait, hold on. This really isn't the kind of place a Grand Duke ought to—"

I ignored Hilda's anxious dithering and pushed the door open. A cheerful chime rang out to greet us.

The shop's interior was far tidier than Hilda's worries had suggested. The weapons on display gleamed with the soft luster of regular care, and not a single cobweb clung to the corners. The floor was free of even the smallest scrap of debris, and for a weapons shop that doubled as a smithy, there was no unpleasant odor to speak of.

Cleaner than I expected.

Had Hilda been keeping the place up for her grandfather's sake all this time? I glanced around the reasonably well-ordered interior and spoke.

"So this is the Ironheart Weapons Shop."

"Miss Hilda said it would be filthy, but it appears to have been quite well maintained. Moreover, every weapon on display is of exceptional quality."

Lucy studied the swords arrayed beside her as she spoke. She had a point. The skill of one of the empire's foremost blacksmiths clearly hadn't gone anywhere. Even at a glance, the keenness of the blades and the overall balance of each piece were outstanding.

I took in the shop a moment longer, absently stroking Lucy's hair, when Hilda spoke up beside us.

"If I may… what kind of sword are you looking for?"

"The Heavenly Demon Sword."

"Ah. I see. The Heavenly Demon Sword? Then right this way… Wha—!!"

Hilda stared at me, her face gone slack with shock. Then she stammered, groping for words.

"W-why in the world would you want the Heavenly Demon Sword?"

"The one I always used broke. I needed a new blade anyway."

"Wait. You do know about the Heavenly Demon Sword, don't you? That thing is cursed. If you take it in your hand, going mad is the least of your problems. You start hearing voices just from getting close to it."

"Don't worry about it. I'll handle it."

I waved a hand at Hilda, who was working herself into a lather, gesturing for her to calm down. I was well aware of how formidable the curse on the Heavenly Demon Sword was. Its previous owner — the knight commander of a certain count's house — had been seized by that curse and slaughtered his entire family, and that was how the blade's infamy had spread far and wide.

But I had something to rely on of my own.

I was about to call for Dunkel so I could see the sword when someone emerged from the back room beyond the counter.

"Hilda! I told you not to concern yourself with the shop. What is it this time? Have you gone and dragged in some two-bit mercenary, calling him a customer?"

"Oh, come on, Grandpa. Don't talk like that. I brought someone incredibly important today."

"Fussing over a shop like this will only get in the way of your future! As I've told you, you have remarkable talent. You ought to forget about the weapons shop already and focus on crafting artifacts!"

An old man with stern brows and a bulbous nose came walking out from the back, laying into Hilda without pause. He was nearly the same height as she was — his head only came up to the chest of an average adult man.

I addressed him at once.

"Are you the proprietor? Dunkel Ironheart?"

"Hm? That I am. And who might you be, coming all the way to a rundown shop like this?"

"Oh my god, Grandpa! Can't you tell just by looking? He's the Grand Duke! The one who saved all those people from the Magic Tower Master at the Sword-Magic Festival! I told you about him — have you forgotten already?"

"Hhhn? The Grand Duke!?"

At Hilda's words, the old man's eyes flew wide.

"I… why would the Grand Duke come to a place like this?"

"As I said, I came to look at a sword."

"A sword? What sword could possibly bring you here?"

"I want to see the Heavenly Demon Sword."

"Th-the Heavenly Demon Sword!?"

The old man cried out, recoiling as if struck. He wiped the sweat from his brow with his collar and pressed on.

"Hah… Grand Duke. That blade is cursed. Curious nobles and brave knights have come to see it from time to time, but every last one of them gave up the moment they drew close enough to hear the voices. It would be best if you turned back now."

"If you're worried about me, don't be. I'd like you to show me the sword."

"I am concerned for you, yes — but more than that, I fear the capital will become a sea of blood. The last man to own that sword was the knight commander of a count's house. He was assessed as an entry-level Sword Graduate. Do you know what became of him once the blade drove him mad?"

‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠

"I heard he destroyed his own house."

"Then you already know. And for the record, in the fighting against the subjugation force, he cut down six Sword Graduates. Do you understand now? If you were to lose control, Grand Duke, it would be hell on earth."

Dunkel's voice shook as he spoke. I could hardly blame him for being this frightened. Even to my eyes, the Heavenly Demon Sword was unmistakably dangerous.

But I needed that sword.

It wasn't as if I wanted the Heavenly Demon Sword just because I happened to be the Heavenly Demon. That so-called Heavenly Demon Sword was, in truth, an Ego Sword — a blade with a will of its own.

The reason its wielder went mad as if cursed the moment they took it in hand was because malignant, corrupted mana — demonic energy — was poisoning them. And those "voices" were simply the Ego Sword running its mouth.

In the original story, Luke had met Dunkel before he'd grown strong enough, so destroying the sword had been all he could do. But if the rampaging demonic energy could be suppressed, it would become as reliable a piece of equipment as I could ask for.

I looked Dunkel straight in his wrinkled eyes.

"Don't you want to be free of that cursed sword?"

"…Even the Church failed to purify it. It is far too dangerous."

"I can unshackle you from it. Leave the blade to me."

"But…"

"Dunkel."

My voice dropped, low and grave. I fixed him with my blood-red eyes and did not look away. He bowed his head without a word, looking for all the world like a man caught in the dilemma of a lifetime.

How could he not be? If I succeeded, all would be well. If I failed, everything ended that very day.

Well? What's it going to be?

The others held their breath and watched. ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠After a long silence, Dunkel clenched his fists and answered.

"Very well. I will show you the sword. If you cannot control it, destroy it at once."

"Understood."

"However — the young lady there will wait with Hilda. There is no telling what may happen. I cannot allow her to come along."

"Lucy…"

"Good grief."

Lucy, who had been standing silently, stepped forward, and Dunkel pressed a hand to his forehead in dismay. He might have been at a loss — but I was deeply moved by what she had said.

After a declaration like that, failure was simply not an option.

I steeled my will once more. Hilda, stubbornly insisting on following her grandfather, came along as well, and together we made our way down to the cellar where the Heavenly Demon Sword was kept.

Our footsteps echoed on the stairs.

"The voices will grow worse the closer we get to the sword. Wrap mana around your body and advance slowly, so that your mind is not shaken."

Dunkel added the warning as we descended the stairs behind the shop. At his words, Hilda hastily clapped her hands over her ears — a pointless gesture, as far as I could tell. The sound wasn't coming through the ears in the first place.

The voice of an Ego Sword was closer to Sound Transmission, or telepathy — it spoke directly into the mind. In other words, something like this:

"Master. A strange noise is filling my head!"

"Grandpa!"

"Stay calm, Hilda! Wrap mana around your whole body and keep your composure!"

The moment the voice entered their minds, the others on the stairs burst into a fluster and drew up their mana.

Huh. To me it had just sounded like a person's voice. Don't tell me everyone else was hearing it as some kind of weird noise?

The further we descended, the thicker the ominous aura grew, and the voice in our heads swelled louder still.

"Grand Duke! It seems even worse than usual today! This is getting dangerous!"

By the time we reached the bottom of the stairs and arrived at the cellar, Dunkel was pouring sweat. Lucy and Hilda both looked distinctly unwell.

What to do? I was fine. It would be a shame to turn back after coming this far. Maybe I should go in alone, at least.

I hesitated only a moment, then opened the cellar door and stepped through.

The stiff iron door groaned on its hinges.

"Grand Duke! It's dangerous!"

"Master!"

Dunkel and Lucy's cries rang out behind me the instant the door swung open. The moment I set foot inside, a chill air licked across my cheek, and the demonic energy flooding the space prickled over my entire body.

Now that was a murderous atmosphere. But where was the sword?

I raised a hand, signaling Lucy to wait, and scanned the room. A single black blade stood driven into the floor at the center of the cellar.

Found it.

The hideous demonic energy pouring off it made it impossible to miss. That was the Heavenly Demon Sword.

The instant I took another step toward it, the voice from before rang through my mind, far clearer than before.

……

……

What in the hell was this?

I stared down at the Heavenly Demon Sword driven into the dark cellar floor, while an unending stream of garbage poured into my skull. I was so blindsided I could only stand there, dumbfounded. First things first — I wanted this damned Ego Sword to shut its mouth.

Let's see… to suppress demonic energy, you had to crush it under an overwhelming volume of mana, wasn't that it?

Drawing on my memories of the original story, I strode up to the Heavenly Demon Sword and seized the hilt.

My grip clenched down hard.

The moment I took the hilt, the Heavenly Demon Sword went even more berserk, spewing filth without pause. I had never seen such a deranged blade in my life. There was no way I was putting up with this.

What now? I almost wanted to just destroy it. No. I should try to subdue it first.

The thought rose as naturally as water flowing downhill. I tightened my grip until the hilt seemed ready to shatter, ignored the garbage still flooding my mind, and poured mana into the Heavenly Demon Sword in a single, overwhelming flood.

Mana surged forth in a rushing torrent—