To repay his father-in-law’s boundless grace, Seo-jun created a supplementary martial art to enhance the Namgung family’s foundational skills.

“This is impossible!” “To think such a martial art could exist in the world!” “I came up with a brilliant method! If I smack my head hard enough, a new martial art will appear the next day!”

How did it end up like this? I just wanted to live a quiet life.

•  

Namgung Sua watched Seo-jun smirk and couldn’t help but burst into laughter herself.

“Seo-jun, what are you thinking?” “Thinking about how my martial art will take over Murim?”

He shook his head, placing the book he was holding back down.

Flash Lightning Heart Art . It was, simply put, a foundational skill.

What set it apart from the Three Talents Mind Method was that it incorporated the unique qualities of the Namgung family, making it easier to build upon.

Seo-jun placed his finger on the cover of the blank book he had received from the headmaster.

Zap—

A faint spark of lightning left a scorched mark on the cover.

The newly inscribed title read: Flash Lightning Azure Thunder Heart Art .

Rather than an evolution of the Flash Lightning Heart Art, it was more accurate to say he added a martial art to enhance its efficiency.

Since the art itself was foundational, he aimed to make it so clear and thorough that even an infant who could barely lift a spoon could understand it. He intended to chew each grain of rice and explain the process as if spoon-feeding it to them.

If someone found this challenging, then they simply had no talent for martial arts and should consider farming instead.

“Hmm. I think this will work nicely.”

He had initially considered incorporating demonic arts but decided it was unnecessary for such efficiency.

Instead, he saved demonic arts for higher-level techniques.

Feeling satisfied, Seo-jun opened the book. The blank pages glared back, his eyes flashing as his fingers moved like lightning.

Flip—

By the time he reached the end of the book, the once-empty pages were now filled with black ink.

A sense of pride washed over him, pleased with his improved command of Hanja.

“Want to read it?”

Seo-jun handed the book to Namgung Sua, whose eyes widened as she carefully turned the pages.

“This is...”

Namgung Sua’s hands moved faster and faster as she read, finally finishing the Flash Lightning Azure Thunder Heart Art in a few minutes. She let out a soft exclamation.

“So, it’s a chant to enhance the Flash Lightning Heart Art? With this, the qi will imbue much more deeply with lightning energy.”

“That’s not the main point. By enhancing the qi with lightning energy, you can increase the flow rate and absorb ambient qi more effectively. It should double the energy accumulation speed compared to using the Flash Lightning Heart Art alone.”

If he had incorporated demonic arts, he could have tripled or even further increased the speed, but it would have caused severe side effects or raised the difficulty.

While Seo-jun thought it might not be that difficult, seeing how Namgung Sua struggled with it made him reconsider.

If it was too much for her, only a few martial artists might handle it, and those individuals were likely practicing advanced rather than foundational martial arts.

“I think it just needs a little more refinement... but I’m not getting any sudden inspiration.”

“More? This is already beyond the level of foundational arts.”

“Come on, Sis. I’m an artisan of martial arts. I can’t leave even the tiniest flaw.”

What would make it better? A distinct feature that would set the Flash Lightning Azure Thunder Heart Art apart from other martial arts.

“Hm...”

When people think of the Namgung family, what comes to mind?

The sky, thunder, sovereignty—those overwhelming presences.

Their swordsmanship embodies gravity, majesty, and that unique swiftness.

Seo-jun’s eyes sparkled as he pieced together his thoughts.

“Lightning seems appropriate, right? The name is Flash Lightning Azure Thunder Heart Art, after all.”

“Huh? Well, yes...”

Seo-jun pulled out another blank book from his sleeve.

“Right, it’s a foundational art. At peak level, wouldn’t they advance to higher martial arts anyway?”

“Usually, yeah.”

“Then why not allow it to grant them access to sword qi even before they reach peak status? Wouldn’t that be helpful?”

“Well... but is that possible? Sword qi is the hallmark of a peak martial artist...”

While arts like that existed, they were often classified as divine arts.

“Come on, nothing’s impossible. Just watch.”

Seo-jun, caught in a storm of inspiration, effortlessly picked out the necessary parts.

Sword qi involves channeling internal energy through the sword to create various effects.

To do that, one must master even a fragment of Sword-Mind Unity, feeling the sword as an extension of oneself, and must also be able to release internal energy.

Those who can are considered peak martial artists.

So how can one wield sword qi without reaching peak status?

“A martial art that lets you produce sword qi as long as you follow the steps.”

Yes, that was it.

Directly handling sword qi might be difficult and dangerous, so he decided to build up from the basics gradually.

Rather than integrating it directly into the Flash Lightning Azure Thunder Heart Art, he created a new linked sword art, the Flash Lightning Thirteen Sword Thunder.

He inscribed the chant with a bright smile, and Namgung Sua’s expression grew curious as she watched him.

•  

The headmaster of the Namgung family, Jin Ga-wi, stared blankly at the books Seo-jun had left behind.

He had intended to express gratitude for their help in subduing the Green Forest Bandits, but Seo-jun had left him something instead.

“So... the young master created martial arts?”

“It seems so?”

Baek-gyeol, Jin Ga-wi’s guard, squinted as he read the titles of the manuals.

Flash Lightning Heart Art. The existing foundational art of the Namgung family.

The ones created by the young master were Flash Lightning Azure Thunder Heart Art and Flash Lightning Thirteen Sword Thunder.

“Master Head, even with his talents, creating martial arts is another realm entirely. We need to test this first...”

“Indeed. What to do about this...”

“I will try them. I should be able to spot any flaws.”

“Oh, will you?”

Jin Ga-wi handed the manuals to Baek-gyeol. He wasn’t entirely sure why the young master had left these with him in the first place.

“Wouldn’t it make more sense for the Heavenly Martial Pavilion Head to review them?”

Since the Heavenly Martial Pavilion Head handled most martial arts manuals in the family, it seemed more appropriate.

“Unless... perhaps the young master had a deeper reason?”

Of course. Jin Ga-wi would have trusted Seo-jun’s word, even if he claimed to spin gold from beans.

Thanks to the young master, his workload had reduced significantly. He could make porridge from beans any time, ten or a hundred times over.

With a relieved expression, Jin Ga-wi spoke to Baek-gyeol.

“I’ll be finishing my tasks, so take a break and test them. The rear training ground should be empty.”

“Yes, Master Head.”

Is this really a break? Baek-gyeol tilted his head and headed to the training ground.

•  

Baek-gyeol skimmed through the manuals.

“No inconsistencies...”

It seemed plausible.

But plausible martial arts didn’t necessarily work.

While he didn’t doubt the young master’s strength, creating two martial arts manuals in such a short time seemed unbelievable.

“Starting with Flash Lightning Azure Thunder Heart Art...”

Having learned Flash Lightning Heart Art previously, Baek-gyeol quickly picked up the new manual.

Though it was somewhat challenging, as a peak-level martial artist, he was able to manage after a few close readings.

He assumed a cross-legged stance and mentally reviewed the chant several times.

“Good. If anything feels off, I’ll stop immediately.”

Closing his eyes, he began circulating his energy.

After a while, Baek-gyeol’s eyes snapped open, surrounded by a blue electric glow.

“This... this is...!”

He stood up and assessed his energy flow.

After only one cycle, a significant amount of internal energy had increased.

“This... is this even possible?”

His energy accumulation speed had nearly tripled, with a faintly heightened lightning energy presence.

“I thought I’d mastered Flash Lightning Heart Art...”

It was beyond that. Following the guidance of Flash Lightning Azure Thunder Heart Art deepened his understanding of Flash Lightning Heart Art.

Had he truly mastered Flash Lightning Heart Art, his accumulation speed would have doubled, but it yielded even greater efficiency due to the improved understanding.

“This is unreal...!”

Baek-gyeol’s hands trembled as he opened the next manual, Flash Lightning Thirteen Sword Thunder.

Would this, too, be at such a level?

“No... Surely not.”

Baek-gyeol composed himself. Flash Lightning Azure Thunder Heart Art alone would be enough to shake the Namgung family.

This was a martial art to reward those who performed great feats, not just basic training.

Not only did it increase energy accumulation speed, but it practically forced enlightenment!

Two such martial arts?

Even a grandmaster could not produce them. He lacked the time alone.

Baek-gyeol skimmed the Flash Lightning Thirteen Sword Thunder manual.

“So, it’s swordsmanship.”

The form itself wasn’t unusual.

“Right. There’s no way he could make two arts of the Azure Thunder’s level.”

Baek-gyeol drew his sword and performed Flash Lightning Thirteen Sword Thunder.

While not remarkable, it was a solid technique.

The blend of majesty, weight, and swiftness was elegant, with swiftness standing out the most.

“Fast sword.”

Swish-shush—

After finishing the sequence, Baek-gyeol exhaled deeply.

“It’s quite strong, though... Hmm?”

He noticed something odd. He hadn’t projected sword qi, so why was there lightning on the blade?

“Huh?”

Alarmed, he tried again.

Zap—

Once more, lightning crackled around the sword.

Not sword qi exactly, but similar. The key was that he hadn’t intended to project sword qi at all.

It implied the art could project lightning through the sword, often considered a divine skill.

“W-what...?!”

His hands shook violently. Swallowing, Baek-gyeol tried Flash Lightning Thirteen Sword Thunder with sword qi this time.

Though fatigued, he swung his sword in a frenzy, driven by adrenaline.

“Ah, ah...!”

What he witnessed was an intensely blue sword qi, thicker than usual.

Only top-level peak martial artists could imbue sword qi with such properties.

He knew he wasn’t at that level.

But behold! His sword qi fiercely crackled with deep lightning energy.

It wasn’t even that difficult.

Divine skills were notorious for their difficulty.

Yet, any Namgung disciple could master this art effortlessly?

Baek-gyeol, breathless, sprinted back.

“M-Master Head! Master Head...!!!”

The Namgung family was in an uproar.