"Mr. Kuro, look at these weapons!" Daiki shouted, excitement glinting in his eyes as he held up a pair of newly forged blades. "These are incredible! Their edges are so sharp they could probably cut down even a king!"
Kuro turned sharply, his gaze narrowing. "What did you just say? Let me see them."
He took one of the weapons from Daiki and examined it closely. The steel shimmered faintly, pulsating with residual energy. Kuro ran his fingers along the blade's edge — and a drop of blood welled up from a small cut on his fingertip. His eyes widened slightly before his expression settled into one of grim satisfaction.
"You were reckless, Ren," he said after a moment, his tone low yet approving. "But you did a damn good job."
"What do you mean?" one of the nearby S-Rank hunters asked, confusion written all over his face. "We don't get it. What's going on?"
Kuro smirked faintly, the scar under his eye twitching as he spoke. "You'll understand soon enough. Just remember this — we've struck gold. These weapons are no ordinary find. They're a jackpot… and they'll change everything in the coming war."
He turned to the blacksmiths and engineers standing nearby.
"Take these immediately. Work together — forge stronger weapons, reinforce every armor piece. No excuses. The clock is ticking."
"Yes, sir!" the smiths chorused, quickly taking the blades and hurrying off.
Ren stepped forward, his cloak rustling as the dim light caught the dark insignia on his shoulder. His eyes burned with resolve.
"You got it. And Yume—" He turned toward her, voice steady but sharp. "Let's train together. We need to erase every weakness before the next battle."
"S-Sure… why not," Yume replied, a faint smile tugging at her lips. She could feel the intensity in his tone — it wasn't a casual request. It was a vow.
The two of them made their way to the organization's central training facility — an enormous underground arena forged to withstand the might of the world's strongest hunters. The steel walls bore scars from past duels, and the faint scent of mana hung thick in the air.
As they stepped into the ring, the atmosphere shifted. Shadows swirled around Ren, while a silver-blue aura pulsed faintly around Yume. They stood at opposite ends, silent but burning with anticipation.
"We'll fight on the count of three," Ren said, voice echoing through the hall.
"Fine by me," Yume replied, her grip tightening on her sword.
They took their stances.
"One…"
"Two…"
"Three!"
Both vanished in a blur. Sparks exploded as blades collided faster than the eye could track. Each strike shook the ground beneath them. The air screamed with every swing, leaving trails of energy that danced like lightning.
"You've grown stronger since our last battle," Ren said between strikes, sweat already forming on his brow. "My hands are actually shaking."
Yume didn't reply — she pressed harder, her movements sharp and fluid, each attack faster than the last. She was relentless, pushing Ren to raise his power higher and higher. Their blades clashed again, releasing shockwaves that cracked the arena floor.
Hunters began to gather around the edges of the arena, drawn by the noise and intensity.
"Who the hell are they?" one whispered. "How can anyone keep up with an S-Rank like that?"
The air trembled — and then Yume unleashed one of her new sword arts. Her blade gleamed with a void-like energy, and when she swung it, the very ground split in two. Ren barely dodged, feeling the heat of the attack graze his armor.
"What was that?!" Ren demanded, landing hard on his feet.
"I told you," Yume said coldly, her eyes burning with focus. "I want to test my strength. If you hold back, you'll die. So stop holding back, Ren!"
Ren froze for a heartbeat — then smirked. "As you wish."
Darkness flared around him. His aura shifted, thick and heavy, and in an instant his body was engulfed in shadow as he transformed into the Knight Form. His armor blackened and cracked with demonic energy.
Gasps rippled through the crowd.
Daiki and Kuro, walking past, stopped dead in their tracks as they saw the transformation.
"Is that… his power?" Daiki murmured, wide-eyed.
Kuro shook his head slowly. "No. That's not even close. What you're seeing is only Ren's raw strength — not the power of the Black Heart, and not the true darkness inside him."
Daiki frowned. "He's grown so much stronger in just a few months. But… is he ready for the truth?"
"No," Kuro said, his tone heavy. "Not yet. The truth must wait until the right moment. For now, he must carry the weight he already bears."
Back in the arena, Ren's aura surged. Shadows coiled around him like serpents, thickening until even the air became heavy.
The ground cracked under his feet.
Then, in the back of his mind, a voice whispered — calm, yet thunderous.
"As you wish, my king…"
The moment the words echoed, Ren's aura exploded. The darkness roared outward, forcing several hunters to step back. The temperature dropped. Even the light seemed to dim.
Yume grinned, exhilarated. "Good! That's what I wanted! Now…" — her eyes gleamed like stars — "show me your full power!"
Ren tilted his head slightly, a dark smirk curling his lips. "Then watch closely, Yume. I'll show you something new."
They lunged at each other again, the sound of their clash ringing like thunder. The air tore apart from the sheer pressure.
"If they're both S-Ranks," a hunter whispered in disbelief, "they could destroy the entire city at this rate!"
Several high-ranked hunters rushed in, alarmed by the overwhelming mana signatures.
"Is this an enemy attack?!" one shouted.
"No… it's them!" another pointed. "They're fighting each other!"
As the dust cleared, someone recognized them.
"Wait — that's Ren Akatsuki!"
"And the one he's fighting… Yume Akegami!"
Even the elite hunters fell silent.
"These two… they're beyond us," one muttered. "Could they be Rank X?"
"That rank hasn't existed in over a century…"
Yume's sword flared with a dark aura, black flames licking along the edge.
"Eternal Eclipse!" she roared, swinging her blade with all her might.
The moment her attack met Ren's katana, a deafening explosion tore through the arena.
BOOM!
Walls shattered. The entire hall was engulfed in smoke and fire. Shattered tiles flew like shrapnel as an enormous shockwave rippled outward.
When the dust settled, a colossal black phoenix emerged from the explosion, its wings unfurling in a storm of shadows. It let out a bone-shaking cry that made the ground tremble.
"What in the world is that?!" a hunter screamed.
"It's… a phoenix. Born from pure darkness!"
Ren stepped through the haze, his eyes glowing crimson. "I summoned it."
As the smoke cleared completely, the crowd gasped — his right arm was missing, blood dripping down his armor.
"Ren!" Kuro shouted in alarm.
Ren was breathing heavily but grinned through the pain. "So… that was your new technique, huh?" he said, voice rough. "Not bad."
Then, before anyone could react, his arm began to regenerate — bone, muscle, skin — all in seconds. The sight left even the S-Ranks speechless.
Yume's expression faltered. "You… healed instantly…"
"Yume," Ren said, his voice calm yet commanding, "you've become stronger than the kings themselves. But…" His aura surged violently, the shadows deepening. "I am stronger."
The darkness around him spiked to 47.5%, swallowing the air itself. The entire arena trembled under the pressure.
He moved — faster than light. In an instant, he appeared before Yume and drove his fist into her stomach with brutal force. The impact sent a thunderous shockwave through the chamber. Yume coughed blood but refused to fall, forcing her body beyond its limits to strike back.
Ren's eyes blazed as he drew his katana once more. Both were at their breaking point — every breath, every movement, pushed them past human endurance.
Then… something shifted.
Ren's aura twisted. The shadows around him began to writhe uncontrollably. His movements became erratic, almost mechanical — like his body was being controlled by something else.
"Ren, stop!" Kuro's voice cut through the chaos. He and Daiki appeared between them in an instant.
"Are you out of your mind?!" Kuro roared. "Do you want to kill her?!"
Ren froze, blinking rapidly. "Wh-What do you mean, Master?"
"That attack you were about to unleash," Kuro said sharply, "would have killed everyone in this arena. At full power, the Phoenix of Darkness could obliterate the entire city!"
Ren's aura shattered as he dispelled the form, panting heavily. "But… I didn't do anything. My body… it moved on its own."
Kuro's expression darkened. "What?"
"When I stopped to catch my breath," Ren explained, still trembling, "my body suddenly reacted — like someone else took control. And just before I released the energy… you appeared."
Daiki stepped forward, his face grim. "Ren, the attack you almost used — it's called Stormshatter Cry Burst. It's one of the most destructive techniques ever recorded. Even a monarch couldn't survive it."
He then turned toward Yume, his tone sharp. "And you — I told you never to use Eternal Eclipse! That technique drains your life force every time you activate it!"
Ren turned to Yume, stunned. "What do you mean?"
Daiki's eyes softened, though his voice remained firm. "That technique can cut through anything. But every swing shortens your lifespan."
Yume tried to smirk, but her lips trembled. "I can handle it. I must master it… because I'm the only one who can wield it."
Then blood spilled from her lips, and her knees buckled. The backlash hit her all at once — her bones cracking under the internal strain.
"Yume!" Ren shouted, catching her before she hit the ground. Her breathing was shallow, her aura fading.
"Somebody bring a stretcher, now!" Ren barked.
"Yes, sir!" Several hunters rushed over, lifting her carefully and hurrying her toward the medical wing.
Kuro placed a hand on Ren's shoulder, his expression somber. "Go with her. Stay by her side. She will need you when she wakes."
Ren clenched his fists tightly, his eyes burning with silent rage and guilt. "I will," he said quietly — but inside, the darkness whispered once more.
"You still haven't seen true power, my king…"