Just One Line

Weger couldn't believe what was happening right in front of his eyes. Just one week. Cael's wrecked body was recovering at a speed that utterly demolished Weger's common sense.

'Now it's about at the level of a normal person.'

When he'd first circulated the Tai Chi Profound Heaven Heart Method, even gathering a tiny speck of energy the size of a mung bean had been a struggle. But once he'd untangled the knotted mess of his qi and blood and opened the channels, the mana overflowing in this world synergized with the nutrient-rich meals Ella prepared with such care, rapidly restoring his flesh.

Of course, relying on internal energy meant his body itself was still frail and skinny compared to ordinary people. But the Tai Chi Profound Heaven Heart Method was peerless when it came to fundamentally rebuilding and improving a weak constitution from the ground up. At this rate, returning to normal was only a matter of time.

'Choosing the Tai Chi Profound Heaven Heart Method as my starting point was a brilliant decision. My body feels so light.'

His current level was third-rate at best. It was an unbelievable growth from a crippled body that couldn't even use martial arts, achieved in just one week.

'At this momentum, first-rate won't be far off.'

His accumulated internal energy was still too scant, so pushing his qi and blood hard left him breathless and exhausted quickly. But Cael loved this sensation of fatigue—the sweat, the muscle aches—as proof that he was alive.

Back in his days as the Heavenly Demon ruling the Shipman Mountain Range, his Return to Youth body never hit a physical limit no matter how much he moved. The heavy pull in his legs, the ragged breathing, the full-body cellular burn from just running—this stuffed, satisfied sense of human limits was something he hadn't felt in ages. A cheerful smile spread across Cael's lips.

"Come on, let's hurry! Ella's probably waiting with our food, dying of hunger!"

"W-Wait a sec! My heart's about to burst—let's rest five minutes!!"

As Weger collapsed spread-eagled on the dirt, Cael clicked his tongue and ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠stopped.

"Tch, and here I thought a big lug like you would have some stamina."

Living with them had made it clear: not just the maid Ella, but this Weger guy too—they truly served and cherished the original owner of this body with heartfelt loyalty. Something about being warmly taken in as kids. Even though Cael had turned into a prickly wastrel tormented by illness, that one warm childhood memory kept them devotedly caring for the forsaken young master of the ducal house.

"Fine, let's rest here a bit."

Cael plopped down on a massive boulder. Cool mountain breeze fluttered by, cooling his sweat. Warm, gentle sunlight poured from a cloudless sky.

'Perfect.'

It was a peaceful, blessed landscape he'd never seen in the Shipman Mountain Range his whole life. Cael quietly closed his eyes, feeling the wind, and this unfamiliar, serene romance-fantasy world started growing on him more and more.

"How the hell is this possible, young master? In just a week, you've gotten healthy enough to outpace me climbing that mountain every day. No ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠one's gonna believe it."

Weger, catching his breath, asked in disbelief.

"Hmm, maybe it's not that I've gotten healthy—maybe you've just been slacking on training and stayed weak?"

"N-No way! Even looking like this, I got top marks in stamina for the territory guard exam! Before coming to the annex, my buddies called me 'Wolf Stamina Weger'!"

Cael burst out laughing at Weger's indignant protests.

"Kukuku, wolf? Oliver's way better than you."

"Woof woof woof!!"

Oliver had raced far ahead, but now flapped his ears as he bounded back, unable to spot them.

"That guy's full of energy."

'Come to think of it, there was that beast martial art from the southern barbarians.'

Oliver was too clever for just a dog. There were times Cael thought he outdid even Weger. Truth be told, Cael had a hidden reason for dragging Weger and Oliver out every morning, enduring the hassle to run the mountain and sweat together.

In his Heavenly Demon days, a single burst of energy let him peer into an opponent's constitution and nature. But now, with barely a mung-bean danjeon, he lacked the capacity for such advanced feats. So instead, he panted and sweated alongside them, closely observing this honest, loyal guy's skeletal structure and muscle usage to pinpoint the perfect martial art branch for his temperament.

'Yeah, dense muscles, sturdy ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠lower body stance. Not flashy swordplay—he'd suit a heavy, destructive mid-length sword. The Jungnam Sect's Thirty-Six Heavenly Swords would fit him perfectly. I'll teach him when the chance comes.'

"Woof!!"

"Kuku, yeah, I'll teach you one too."

Weger, resting nearby, tilted his head.

"Teach what, sir?"

Cael smirked at him.

"Something like that."

After that sweet rest, Cael returned to the annex with light steps. But the moment he crossed the open gate, his sharp qi sense caught Ella's presence—and a stranger's.

"Hm? Someone's here?"

Cael halted, narrowing his eyes. Inside the living room stood a mysterious man in a deep gray cloak pulled low, talking with Ella.

"Who're you?"

At Cael's question, the cloaked man spotted him, lowered his hood slightly, and bowed politely.

"It's been a while, Cael. I'm here on behalf of the main house."

"Main house?"

"Yes, by order of Acting Duchess Silina."

Cael already knew that was his stepmother's name—he'd studied hard with Ella and Weger over the past week.

"From Mother? What's this about?"

"Nothing major. Just checking if you're doing well in the annex, how your health is."

The man's eyes quickly scanned Cael up and down. Cael snorted inwardly as he met the gaze.

'This guy's no ordinary messenger. He wields a sword—a killing blade.'

In the martial world, it'd be laughable first-rate at best, but stronger than current Cael.

'Sending a killer swordsman just for a messenger? Really?'

"Well, we've confirmed you're fine. Take care of your health."

With those loaded words, the cloaked man left without lingering. Weger glared suspiciously at his back.

Cael turned to Ella, asking what the man had said.

"Ella, what'd he ask?"

"Uh, just about your health and recent status."

"What'd you tell him? That you were on death's door a few days ago, but fine now?"

"Did you mention losing your memories or anything?"

Ella bowed her head, face crumpling.

"S-Sorry. Should I not have...?"

Cael smiled.

"No, you did great. It's more believable coming from you than me."

"Huh?"

"Never mind. What's for lunch?"

Ella brightened, introducing the menu.

"Oh! Fresh chicken came in today, so I made herb chicken broth for lunch!! Your favorite, young master!"

Herb chicken broth. A nourishing dish of simmered fragrant herbs and chicken, eerily similar to Korean samgyetang or baeksuk just from the smell. Cael's eyes lit up.

"Oh yeah? Perfect timing—I'm starving after the mountain. Let's eat."

"Hehe, yes! The chicken turned out super tender today!"

Ella beamed, her usual cheerful energy as she set the table.

'Out of nowhere from the main house...'

He needed to look into it.

'But first, this.'

Diamond Mountain also came after a meal, right?

With his belly full, Cael sank into thought.

'Hmm, sending a first-rate level expert just for a messenger.'

Over the past week, he'd grilled Ella and Weger on ducal house matters. But they'd been here in the annex for years, practically abandoned, so they knew little of the inner workings—just the family tree, which Cael had memorized too.

Stepmother Silina. The woman from the novel Sword Duke's House who tormented the protagonist countess's daughter mercilessly. Insatiable for power, no scruples for her gain.

'And... probably the one who killed this body's original owner.'

The reason even the Heavenly Demon ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠hadn't recalled Cael upon hearing the name: in the original work, this Cael appeared in just one line. An indirect mention at that. Drawing on his Heavenly Demon memory, Cael recalled the passage.

'First wife's eldest son. That's me.'

The Restis family's eldest son, mentioned in just one line. That was Cael's identity.

Rapidly weakened after his mother's death? No way without cause. "Died of illness"? That greedy stepmother probably did it. And a ducal house couldn't save one sick heir?

Cael chuckled instead.

'No easy path, huh. Central Plains threw me in hellish training grounds; now it's assassination?'

And he was far weaker now than then.

'I planned to take it slow, but no time for that.'

Cael sat in lotus position, preparing to circulate a heart method different from the Tai Chi Profound Heaven Heart Method he'd practiced so far.

Heavenly Demon Illusory Art. The one that elevated him to unrivaled supreme.

Circulating the Tai Chi Profound Heaven Heart Method these past days had revealed something: it was surprisingly half-baked. Zhang Sanfeng—founder of Tai Chi Fist, inner alchemy cultivator who ascended to immortality, martial artist and Taoist. And in his later years, he exorcised ghosts.

From that, Cael inferred: this heart method didn't operate on a single energy type.

'Tai Chi is ultimately yin-yang harmony. What Sanfeng pursued was balance. Harmonizing the pure vital energy of the living and the death qi of the departed.'

He'd thought demonic qi and pure qi couldn't mix, but the Tai Chi Profound Heaven Heart Method could harmonize them into something entirely new.

'If not?'

Cross that bridge when he came to it. Dive in headfirst—that was how Heavenly Demon Cheon Woo-jin survived the murim world.

'Here goes.'

Wooooong—

The Heavenly Demon Divine Art he'd cultivated for decades began anew, right here.