Curious, Lin Mu let the sword rest within the sheath for another hour.
By the time he checked it again, it had reached
high-grade
.
Now it truly looked like a proper weapon. The metal shimmered slightly, resonating faintly with his own sword intent. It had potential. Still, it was a basic spirit swordâlow ceiling, low foundation.
"Letâs test your ceiling," Lin Mu said softly, letting it rest again.
This time, the transformation was not as fast.
An hour passed. Then two. Four. Six.
Only after six full hours of nurturing did the sword finally reach the
peak of the spirit grade
. Lin Mu pulled it out, examining it under moonlight. The blade vibrated faintly, eager and alive. Even its sword spirit had begun to coalesceâfaint, immature, but present.
Lin Mu nodded to himself.
"So growth speed decreases as quality increases," he muttered, noting this down in a mental ledger. "Even without materials, you pushed it this far. Not bad at all."
But he wasnât done.
Now it was time for a true test.
He reached deeper into his ring and pulled out a
low-grade Immortal Sword
âone of many he had picked up over the years. These swords were much harder to refine, forged in Immortal Fires, and bathed in rare Immortal Oils to quench. Their cores were denser, and their evolution exponentially harder.
He placed it in the
Sword Cradle Divine Sheath
and focused.
This time, the response was...
quiet
.
Hours passed.
A day.
Three days.
A week.
And still, the swordâs aura remained unchanged.
Lin Mu frowned, pushing his Immortal Sense deeper into the sheath, searching for clues. But the
Divine Sheath
didnât speak. It didnât reject the sword, but it didnât accelerate its growth either.
It was as if it was waiting.
"Materials... do you need them?" Lin Mu asked aloud, half to himself.
He rummaged through his ring and began feeding the sheath with some leftover resources: refined ores, sword-nurturing metals, half-forged scraps. Still, no reaction.
Then, remembering how his old sword nurturing box worked, Lin Mu offered a
batch of Thousand Refined Iron
âan incredibly durable and reactive material, often used in forging High-grade weapons.
The sheath pulsed.
It was faint, but it was thereâa ripple of approval. A signal that it had accepted the offering.
A smile touched Lin Muâs lips. But the sheath didnât immediately begin work. Instead, it stored the materials like fuel, slowly feeding it to the sword over time.
"This wonât be fast," Lin Mu realized. "Not like the spirit swords. Immortal swords require more effort."
He checked again a week laterâand the sword had reached
mid-grade
. That alone was impressive. Under ordinary circumstances, upgrading an immortal sword to a higher tier required
a specialized forge, a high-ranked blacksmith, and a fortune in materials
.
And here the sheath had done it... silently, patiently, and precisely.
Another two weeks passed, and the sword showed no signs of advancing beyond mid-grade. Lin Mu decided to get creative. He poured in
over a ton of Thousand Refined Iron
and several rare alloys used for channeling sword qi. Still, there was no immediate change.
But the sheath
accepted
everything.
Then, finally, a pulse.
Lin Mu instinctively knew what it meant.
"Itâs going to take months," he whispered, running his fingers along the plain exterior. "Maybe a year. But itâll do it."
The sheath had assessed the sword. Understood its structure. Measured its potential. And now, with the materials absorbed, it would begin the slow,
methodical process
of refining it toward the
high-grade Immortal level
.
"The barrier between low to mid and mid to high... really is vast," Lin Mu noted.
But he didnât mind.
After all, he had time. He had resources. And more importantly... he had
patience
.
This was only the beginning.
With the
Sword Cradle Divine Sheath
, he didnât just wield a new weapon.
He wielded the power to
craft legacies
, to
grow legends
, and to
forge a future
.
And this... was only the first test.
Now that Lin Mu had tested the Divine Sheathâs powers on mundane and immortal-grade swords, he finally turned his thoughts toward his two oldest companionsâ
Afternoon Pine
and
Ocean Raker
.
Both swords had been with him through thick and thin. They had weathered storms, battles, and countless cultivation trials. Though their forms were elegant and sturdy, they still bore the invisible marks of their long journey with him.
Each had grown steadily under his care, their sword spirits slowly taking shape, their edges becoming keener with time. And now, after years of nurturing, both stood at the top of the
High Grade Immortal Sword
levelâjust a step away from the
Peak Grade
.
Originally, Lin Mu had estimated that it would take
tens of years
, maybe even
a few decades
, of focused nurturing using sword arrays and Immortal qi and Dao infusions to push them into the final stage.
The process, while natural, was slow and required constant monitoring to avoid imbalance in their growth. This was why he had placed them into a specialized
Sword Nurturing Box
, one he had painstakingly built from rare materials collected across several years and from spoils of battles.
But with the
Sword Cradle Divine Sheath
now in his possession... those old methods suddenly felt
outdated
.
The Divine Sheath had
absorbed
his sword nurturing box without hesitation, as if dismissing its limited capabilities entirely. And while Lin Mu had been shocked at first, he now understoodâ
the Sheath was simply beyond it
. Beyond anything he had ever seen.
He closed his eyes, focusing his
Immortal Sense
into the Sheath.
Within its internal space, a boundless quietude reigned. He felt the presence of
Afternoon Pine
and
Ocean Raker
, both resting calmly within its depths. Their auras fluctuated gently, as if enjoying a warm spring day, basking in the nurturing waves that radiated from the Sheathâs core.
Their growth was already beginning to accelerate.
Lin Mu felt a tugâa soft pull on his
immortal qi
. Not sharp or draining, but steady. Like a tide slowly being drawn in. It was almost negligible, and under normal circumstances it mightâve gone unnoticed.
But Lin Muâs cultivation had reached such heights that he could detect the faintest of fluctuations in his qi cycle.