The storm above Tetsujin's Peak raged with unnatural fury.
Lightning clawed the heavens like a god in torment, and thunder shattered the air in rhythmic booms that echoed down into the valleys below. Wind screamed between jagged rocks, carrying with it the scent of ozone and battle—ancient and imminent.
Raijin stood at the summit, his cloak whipping around him like a living shadow. His eyes burned with an inner storm, blue irises flickering with electric arcs. The weight of what was to come settled on his shoulders, heavier than any armor he'd worn before. This was no ordinary duel. This was not just to test strength, nor simply challenge power.
This was to prove something far deeper.
To himself.
To Shinkū.
To his father—Kurogane Tetsujin.
The final words from his father still echoed in Raijin's mind: "You are not ready. You are not him."
Not ready?
The wind surged, scattering pebbles across the summit like a flurry of knives. Raijin clenched his fists and exhaled slowly. He had spent years mastering his control, perfecting his lightning-infused kenjutsu, honing every fiber of his body and spirit into a conduit of thunder. Yet still, Kurogane's words haunted him.
That he was not Shinkū.
That he lacked the void within.
But I am not trying to become Shinkū, Raijin thought bitterly. I will surpass him.
Below the summit, the disciples of Shinkū advanced cautiously, feeling the charged air, each of them tense. Mei was the first to speak.
"That's not just natural lightning," she murmured, her eyes tracking the streaks of white that cracked across the black sky. "The energy is focused. Directed."
Gorou nodded. "It's him. Raijin. His aura's covering the entire peak."
"Feels like he's angry," Kaito added, blades half drawn, though not in threat. "But not reckless. This is something else."
They had seen their master face death and god-like Jūshin. They had watched him wrestle void-born horrors and emerge still breathing. But even so, the pressure of Raijin's thunder made the hairs on their necks rise.
Shinkū, silent and statuesque, led them. His crimson scarf fluttered against the wind, his eyes narrowed. He could sense Raijin's intentions now—not hatred, not malice.
Conviction.
The kind that couldn't be brushed aside. The kind that split mountains.
---
Raijin waited atop the stone platform carved by ancient hands. The platform bore markings from another time—weathered runes of a clan that once harnessed sky and storm. He turned as Shinkū and the disciples reached the plateau.
"You came," Raijin said, his voice steady, almost calm.
Shinkū met his gaze, unreadable. "You called."
Thunder boomed again. The air was sharp with tension.
"I didn't come to kill you," Raijin clarified. "But I will defeat you."
Silence. Even the wind hushed for a moment.
"I figured as much," Shinkū said. He stepped forward, the void whispering around his feet like faint shadows of memory. "This isn't just about power, is it?"
Raijin's jaw clenched. "No."
He glanced at Mei, Gorou, and Kaito—then back to Shinkū.
"This is about proving to him… that I am more than a replacement. That I am not walking in your shadow. That my thunder is mine alone."
Kurogane Tetsujin had trained both of them—Raijin as his son, Shinkū as his chosen student. In the clan, it was whispered that the void-born boy had surpassed even the blood heir.
Kurogane never denied it.
Shinkū studied Raijin carefully. "And you think defeating me will prove that?"
"No," Raijin replied. "But it's the only place to start."
---
Mei stepped forward. "Raijin… are you sure about this?"
He looked at her. For a moment, something flickered in his eyes—regret, maybe. Or nostalgia.
"You were always the one who understood silence," he said. "Even when we trained side by side. But some silence… has to be broken."
A bolt of lightning crashed behind him. He drew his blade—Raikōzan, the Thunderlight Edge—and it hummed with electric fervor.
Shinkū stepped forward, his expression hardening.
"Then I accept."
His disciples tensed, but he raised a hand. "No interference."
Gorou opened his mouth but closed it again. Mei bit her lip. Kaito simply nodded. They stepped back.
The wind turned cold.
---
The duel began not with motion, but stillness.
Raijin exhaled, his breath forming frost. Shinkū lowered his stance, eyes glowing faintly as the void around him deepened.
The first strike came with sound and fury—Raijin vanished in a thunderclap, appearing inches before Shinkū in a flash of light. His blade came down, cloaked in searing voltage.
Shinkū tilted, just enough to avoid the edge, his own arm swinging in a precise arc, palm coated in a thin film of void. The two forces met—thunder and emptiness—and a blast of pressure cracked the platform beneath them.
They separated, neither gaining ground.
Raijin smirked. "You're faster."
"You're louder," Shinkū replied.
The next flurry was less playful.
Raijin became a blur, his movements choreographed lightning. He struck from above, below, the side—each swing backed by bursts of explosive current. The air lit up with sparks and white-hot arcs.
Shinkū countered with a silence that swallowed sound. The void around him absorbed impact, redirected force, turned Raijin's power into nothing. But even nothing had limits.
One swing clipped his shoulder. Another grazed his side.
He was bleeding.
Raijin saw it. "I can hurt you."
Shinkū didn't respond. He surged forward, the void flaring—not wild, but surgical. His fist hit Raijin's chest, sending him skidding back several meters.
Raijin coughed. The hit hadn't broken bone, but it rattled his core.
He's holding back, Raijin realized. Damn it, he's still holding back.
---
Below, Mei clenched her fists. "This is more than a duel."
"It always was," Kaito said.
"They're not fighting just each other," Gorou added. "They're fighting everything they carry."
The past. The legacy. The pain.
---
Raijin shouted and lightning poured from him like a flood. The skies responded, sending bolts to dance around his form. His blade extended, crackling with raw voltage.
"I won't be your shadow anymore!"
He struck, and the heavens answered.
Shinkū raised a single hand.
Void met thunder.
A blinding flash consumed the summit—wind, light, silence, and chaos all at once. Rocks shattered, the ancient platform cracked, and a storm roared into being.
When the light faded, both warriors stood, breathing hard. Raijin's arm shook. Shinkū's scarf was torn. Both were marked.
"I see now," Shinkū murmured. "You don't want to be me."
Raijin's voice trembled, not with weakness—but with clarity.
"No. I want to be more."
The void pulsed behind Shinkū.
The lightning danced around Raijin.
Two forces, born from different worlds, stared across the fractured stone.
And then—
They charged.