A counter-formula (破解式).

A technique devised by analyzing a particular martial art or sword style and targeting its weaknesses. By its very nature, it was a thoroughgoing countermeasure. A properly devised counter-formula gave its user an overwhelming advantage against someone trained in the art it targeted. It was, in a sense, a cheat sheet with the answers to a particular exam.

That was why Xue Rong felt as though the very definition of a counter-formula he knew had been shattered.

'Is that even possible? To devise a counter-formula against a person rather than a martial art?'

He could have understood it if Limon had discerned and countered some martial art the young man used. Even the most profound secret art was ultimately a set of techniques. If it could be taught and learned in a fixed form, a counter-formula could be devised against it. That was why, since ancient times, martial artists had guarded their arts so strictly, passing them down to a single successor or refusing to teach them to outsiders, and why they would stake their lives on a single secret manual.

But what Limon was teaching Wei Ling over the phone was not a counter-formula for a martial art. It was a countermeasure for the knife-wielding young man himself.

["Dark Metaphor Summons the Soul. Crossing Stance."]

Wei Ling spun like a top. As the sweep of her clothes obscured the young man's vision, she slipped her sword into his blind spot and thrust. He leaned his head back to evade it. Just as he moved to counterattack—

THWACK!

"Gah?!"

Her other palm struck his jaw instead of her sword. The sword had been a feint from the start. The real blow had come from her other hand.

The frightening part was that Limon had given that instruction before she launched her attack, as though he had known from the outset exactly how the young man would dodge. The rest of the exchange was no different.

["A Hundred Transformations Fall Upon the Hand. Rousing Stance."]

She caught a knife thrown without warning with a flowing sweep of her sword, like petals scattered across rippling water.

["Twin Peaks Clear the Road. Flowing-Heaven Stance."]

She nudged the two knives he had drawn in secret sideways, making them collide with each other.

["Shark in the Flying Spring. Flashing-Lightning Stance."]

She stabbed his thigh before he could kick to buy time and retreat to regroup.

Whether he attacked or defended, Wei Ling cut off every move before he could make it. Her responses were so thorough that the man who had seemed impossible to fight only moments ago now looked like a butterfly caught in an invisible net.

"What the hell is this?! Are you using 『Future Foresight』 or something? No, even for a prophecy skill, this is ridiculous!"

The young man burst out shouting in frustration. It was a reasonable conclusion. Short of a prophecy-type skill, how could anyone shut down his every move so perfectly?

The trouble was that Limon, issuing instructions to Wei Ling, was doing something far beyond what common sense allowed.

'He's picked apart every detail of that bastard's thinking and habits, and he's calling out sword forms that anticipate and counter his movements!'

This was no longer a counter-formula. It was more like a strategy guide: analyze when and how a raid boss followed its patterns, then work out how to beat it. Limon had read the young man in the clown mask so completely that he had devised a counter-formula guaranteed to win.

'... What level of mastery would it take to do this without even seeing him?'

If Limon had been here watching the young man fight and calling out counters in real time, Xue Rong might have understood. It was only natural for a master to read a less skilled fighter's moves. But Limon was not here. Xue Rong could not even imagine how vast the gap between them must be for Limon to give such flawless instructions over the phone.

'No, even so, he couldn't devise a counter-formula without knowing the man. When did the Sword Lord ever meet him?'

As Xue Rong wondered how Limon could have analyzed a young man he had never seen in such detail, his eyes suddenly widened. He had realized there was one point of contact between Limon and the young man—perhaps the only one.

'Don't tell me... the autopsies?'

When the massacre at Black Dragon Construction took place, Limon had examined hundreds of bodies, one by one. It was not widely known. But Xue Rong knew because he had been going around looking for faults in Limon's work, and that knowledge led him to a terrifying possibility.

'He read everything about that bastard just from the wounds left on the bodies?'

In theory, it was not entirely impossible. A medical examiner with the 『Autopsy』 skill could learn a great deal merely by examining a body: the murder weapon, the method of killing, characteristics of the culprit. Likewise, a profiler with 『Criminal Psychology Insight』 could read a criminal's personality and behavior patterns. But theories remained theories because putting them into practice was difficult. Even the Tracers who had investigated Black Dragon Construction had failed to uncover much detail about the killers. What if Limon had discovered what even the Tracers could not, relying only on his experience and keen eye—and then devised a way to counter the killer?

'... Limon Aspelder.'

A chill ran through Xue Rong. If his guess was right, it was only natural that Limon knew the Voidless Advancing Sword Style's forms and even their variations well enough to direct Wei Ling perfectly. Limon and the Seven Dragons Society had fought for hundreds of years, from the Bronze Age through the Age of Heroes. A man who could learn everything about a killer from the wounds on corpses could hardly have failed to discern the secrets of the Society's arts after countless battles against them. In that sense, Limon might know the Seven Dragons Society's Seventy-Two Martial Schools better than anyone. Perhaps even better than its own members.

'Humanity's last Sword Master.'

Xue Rong had thought him no more than an outmoded relic. He had never doubted that if the Seven Dragons Society truly committed all its strength, and added the power of a Monarch, it could easily kill even Limon.

But could it really? If they staked everything on a single decisive battle, could they truly defeat Limon? That monster who had stood against the seven dragons that had devoured even gods, then spent hundreds of years defending the world and reigning at the pinnacle of humanity?

'Our ancestors... fought a monster like that?'

His faith was crumbling. Doubt crept into convictions that had once been unshakable. Amid that overwhelming confusion, Xue Rong could only look at Limon with fear in his eyes.

* * *

While Xue Rong trembled with fear, someone else was trembling for an entirely different reason.

["Drunken Serpent Sways. Rebounding Strike Stance."]

CLANG-CLANG-CLANG-CLANG!

Thrust, deflect, swing. Wei Ling had done it for nearly half her life. She was performing forms so familiar from repeated training that they were all but engraved in her instincts. There should have been nothing new about them. Yet at this moment, her own swordsmanship felt profoundly unfamiliar. It wasn't only because she could do more than hold her own against a superior opponent: she was driving him back with a one-sided assault.

Limon's instructions, tailored to the situation, made familiar forms strange in his languid voice.

["Great Frog Swallows an Egg. Unhurried Stance."]

This instruction was a perfect example.

As its name suggested, Great Frog Swallows an Egg was a form that thrust the sword out suddenly, like a frog darting its tongue at prey. But Limon told her to thrust slowly, even incorporating Unhurried Stance, a variation of a different form. Anyone could see that it was insane. It would hand the enemy an obvious chance to counterattack. Yet the result was different.

SLASH!

"What the fuck?!"

Like a batter swinging for a fastball and missing a slow changeup, the young man tried to dodge and counterattack when her seemingly perfect lightning-fast sword suddenly slowed. Instead, he moved straight into the blade and had his cheek cut. Even Wei Ling, who had done it herself, could scarcely believe the result.

Most astonishing of all was the flow of psionics. The Seventy-Two Martial Schools were martial arts and secret disciplines: methods of training created by the great seven dragons to pass their own power, psionics, on to humans. Every form in those schools had its own flow of psionics. Mixing those flows indiscriminately could send a practitioner into a fatal backlash, leaving them crippled or dead.

But the seemingly haphazard forms Limon called out never disrupted the flow of her psionics. On the contrary, they made it surge higher, gathering into a powerful current like a flood. Each time Limon called out a form, each time she swung her sword as instructed, her psionics grew stronger. As that power raced through her energy channels, her sword grew faster and fiercer.

"What the hell's going on? You weren't this good before, comrade! Why are you so fierce now?"

["Black Lotus Touches the Water. Swift Surge Stance."]

CLANG!

The young man was saying something, but Wei Ling paid him no mind. Immersed in the flow of psionics, she continued wielding her sword as though entranced.

'This is the Voidless Advancing Sword Style?'

Wei Ling had believed it was a secret art built on stealth, its true strength lying in ambush and assassination. But the Voidless Advancing Sword Style Limon was teaching her now was different. Rather than hiding her body, she suppressed her presence to confuse her opponent's senses. She read his mind, slipped into his blind spots, and struck where he least expected it.

Empty the self (無空). Leave only the advancing sword (進劍). Become one with the sword (身劍合一).

The ultimate essence of the Voidless Advancing Sword Style, which she had never grasped before, was being etched into her body. And that was not all Limon, the last Sword Master, was engraving there.

["Secret Scripture Upon Secret Scripture, Northern Reach Stance. Palace Carving Leaves Its Mark, Precise Strike Stance."]

Forms chained together out of sequence. Variations that had once stood apart fused into one. The interplay of the two produced countless sword moves. Endless possibilities kept emerging from the Voidless Advancing Sword Style, an art she had thought she knew completely, and her heart raced.

'—This is fun.'

She had lived her life believing a sword was merely a tool and swordsmanship merely a means to an end. But right now she could not see them that way. Becoming one with her sword was a joy. Learning new forms was a joy. Feeling her psionics surge was a joy. All of it lifted her spirits like a child receiving a birthday present, and for the first time in her life she felt the joy of wielding a sword. She wished the moment could last forever.

Unfortunately, that wish remained only a wish.

["Let's see. By now he should have five or six wounds. Time to finish this."]

At that moment, Wei Ling realized that even a swordsman as extraordinary as Limon could be wrong. His insight was not perfect after all.

Was it because she had come out of her trance? Or simply because his instructions had stopped? Swallowing the disappointment that rose as her joy rapidly faded, she spoke as calmly as she could.

"There's no need."

["Huh? Why not?"]

"It's already over."

["Over? What's over?"]

"I've already severed both the killer's arms and have my sword at his throat."

["... Why have you won already? I haven't even taught you the ultimate form yet."]

"Exactly."

If only the fight had lasted a little longer, she could have learned that form too. Wei Ling lamented her bad luck in facing such a weak enemy, while Limon sounded distinctly put out.

Listening to them, the young man lay pinned beneath Wei Ling's foot, both arms severed. Through a tear in his mask, his face showed utter disbelief as he muttered, "I'm the one who lost his arms and the fight. What am I supposed to do when you comrades sound so disappointed?"

Limon's answer was blunt.

["What do you think, you little shit? Drop dead already."]