Standing at the doorway, Horitake gazed up at the heavy, roiling storm clouds, then down at the Nichirin Blade Weiguang in his hand.
The purple arcs of electricity dancing along Weiguang's blade surged higher, pointing defiantly toward the heavens!
The storm clouds above seemed provoked, churning and surging with violent intensity.
Witnessing this phenomenon, Tetsutake's jaw dropped in disbelief.
"M-Masaka…"
Boom! Crack!
A deafening thunderclap erupted, and a bolt of blue lightning streaked from the sky, aimed straight at Horitake!
The sudden flash nearly blinded everyone, the explosive roar threatening to deafen them. In the face of such celestial might, any living being would instinctively tremble!
Zenitsu, ever timid, felt his legs give out. Clinging to the doorframe, he stared at the purple arcs flashing upward from Weiguang, his pupils unfocused as he muttered the truth in a trembling voice:
"Could it be… Weiguang is challenging the heavens' thunder?"
Tetsutake clutched his head, incredulous.
"How is this possible!? How can a blade possess its own spirit? To dare provoke the sky's thunder!? Did I unwittingly forge a divine artifact!?"
Crack! Boom!
Two more bolts of lightning flashed through the clouds, accompanied by a massive, reverberating roar.
At that moment, the system's voice echoed in Horitake's mind:
Ding! The host has acquired a blade that should not exist in this world and named it with a title that should not exist, triggering a negative butterfly effect: The Trial of Heavenly Thunder!
*Ding! System Mission Issued:
Resolve the negative butterfly effect, the Trial of Heavenly Thunder!
Weiguang's emergence is not tolerated by this world's heavens.
A mere Nichirin Blade, Weiguang dares to challenge the sky's thunder, incurring the wrath of heavenly lightning intent on destroying it!
Host, wield Weiguang to defeat the heavenly thunder and overcome this trial!
Friendly Reminder: If you lack confidence, young one, abandon Weiguang. It will be obliterated by the thunder.
However, as a consequence, no weapon will ever acknowledge you again. No sentient weapon will follow someone who abandons their blade.
Mission Success Reward: Breath of Thunder evolves into Heavenly Thunder Breathing!
Mission Failure Penalty: At best, Weiguang is destroyed; at worst, the host faces death and dissolution!*
Horitake listened to the mission, his face expressionless.
Truly, he'd been backed into a corner. You damned system! Did he have any other choice!?
And you, damned system! Why be so vague? Calling it a "Trial of Heavenly Thunder" when it's clearly a heavenly tribulation!
In some tales, when certain artifacts or elixirs come into being, the heavens reject them, sending down tribulations to destroy them! Those that survive are perfected; those that fail… well, don't they face death and dissolution?
How bizarre—it's as if he'd stumbled into the wrong story.
This was the world of Demon Slayer, not some xianxia realm!
Letting out a long breath, Horitake stilled his mind, anchoring himself to his resolve.
At this point, there was no turning back. He had to face it head-on—success or failure hinged on this moment!
Gripping Weiguang, its purple lightning crackling, Horitake strode purposefully out of the house onto a wide clearing. He looked up, the sky above him encircled by one bolt of lightning after another.
Seeing his solitary figure beneath the storm, Jiuro couldn't hold back. Braving the relentless thunder, he shouted,
"Horitake!"
Horitake glanced back, meeting the gazes of the three at the doorway. He flashed a faint smile.
"Sorry, old man. This is something I must face alone. Stay back—don't come near!"
Zenitsu stared at Horitake, clutching his head in despair, muttering,
"It's over, it's over! He's doomed! That's nature's thunder! How can anyone withstand it? Big Bro's gonna…"
"Shut up!"
Furious, Jiuro swung his cane, landing a heavy blow on Zenitsu's head, leaving a swollen lump!
Zenitsu yelped in pain, clamping his mouth shut.
It was the first time Jiuro had struck Zenitsu so fiercely. Who could blame him when Zenitsu's words were so infuriating?
Biting back the pain, Zenitsu didn't dare make a sound. He knew his words deserved the hit—they were practically cursing his big brother!
It was an accident; Zenitsu's timid, pessimistic nature had let those despairing words slip out.
Outside, the storm clouds unleashed relentless blue lightning, flashing and roaring with increasing frequency, forming a thunderstorm that brought neither rain nor wind—just thunder!
The dark, rumbling sky, streaked with blue bolts, faced Horitake, who stood alone with Weiguang's purple lightning, defying the heavens' wrath.
Suddenly, he burst into bold laughter.
"Hahaha… My strongest move right now is Raikiri, and Kakashi once used it to cleave lightning itself!
Now, with Weiguang provoking the heavens, I face divine thunder. Isn't this fate!?
Hahaha…"
The storm clouds seemed enraged by Horitake's laughter. All lightning ceased abruptly, leaving only the churning clouds, as if brewing something massive!
In the house, Jiuro, Zenitsu, and Tetsutake's hearts clenched. They knew the moment was near.
Weiguang in Horitake's hand also dimmed its purple arcs, as if gathering strength.
The clouds above swirled into a massive vortex, its center directly above Horitake!
Gripping Weiguang, Horitake fixed his eyes on the sky, not a trace of fear in his gaze—only wild excitement!
"Everyone! Didn't you want to know where the name Weiguang came from!?
I'll tell you—it comes from a phrase I once heard, one that fits my situation perfectly!
There are always beings on this earth who dare to face the majesty of thunder!"
At the vortex's center, the heavenly thunder was ready. Horitake could even see blue light beginning to spark!
Now was the moment!
"Breath of Thunder, Second Form: Full Power, Overload…"
Crackle, crackle, crackle…
Dazzling purple lightning surged from Horitake's body! The electric currents flowed along his arm into Weiguang, igniting the blade into a radiant, crackling purple beacon!
From the sky, a bucket-thick bolt of blue thunder roared down, aimed straight at Horitake!
Horitake leaped upward with all his might!
Brandishing Weiguang's blade, he unleashed Raikiri, slashing head-on at the descending thunder!
"Raikiri!"
Above, the blue heavenly thunder; below, the purple mortal lightning. Which would prevail?
The thunder and Horitake collided in midair, unleashing a piercing, ear-splitting screech!
Jiuro, Zenitsu, and Tetsutake, watching from below, were momentarily blinded by the explosive flash and dazed by the shrill resonance!
But the flash lasted only an instant, and they saw what followed!
In midair, Horitake, wielding Weiguang, cleaved the heavenly thunder!
The bucket-thick bolt split into two, crashing into the peach orchard on either side, obliterating several trees!
Horitake had succeeded.
But his body overloaded in that instant!
He plummeted from the sky, crashing to the ground.
"Horitake!"
Jiuro, Zenitsu, and Tetsutake rushed out, scrambling toward him, desperate to check on him.
The heavenly thunder meant for his trial had been overcome. The clouds, unable to destroy Horitake, reluctantly dispersed, thin rays of sunlight piercing through.
As the three reached him, the thick clouds were already fading, scattered beams of light breaking free.
They gathered around Horitake, anxiously checking his condition, calling out to him.
Horitake lay on the ground, eyes wide, his right hand tightly gripping Weiguang. His body trembled, faint blue arcs of electricity sparking across him—clearly, he'd been struck hard.