The atmosphere was silent. Only the sound of the wind could be heard as it moved across the open field.
Ren stood opposite his father, shadows coiling around both of them like restrained beasts waiting to be unleashed.
"So, Father… shall we continue?" Ren asked calmly.
Zenkai studied him for a brief moment. There was no mockery in his eyes—only acknowledgment.
"I have to give it to you, Ren. In such a short amount of time, you have grown tremendously."
His voice hardened.
"But…"
He vanished.
Not explosively. Not dramatically.
Simply gone.
Within a millisecond, he appeared directly in front of Ren.
"You still have a long way to go."
A single strike.
It wasn't wide. It wasn't reckless.
It was precise.
Zenkai's fist struck the exact seam between the layered plates of Ren's shadow armor—right where the energy flow connected.
A sharp cracking sound echoed across the field.
Ren's body was sent flying backward. The ground split beneath him as he crashed, sliding several meters before stopping.
Yume gasped.
The section of armor where his father had struck was completely destroyed. Not dented. Not chipped.
Destroyed.
Ren forced himself upright.
"This attack… what was that?" he muttered.
It hadn't felt overwhelmingly powerful.
It felt surgical.
The shadow energy responded to his will, and the broken portion of his armor regenerated quickly, reforming into its original shape. Blue sigil veins pulsed across its surface once more.
Ren stood again.
He is powerful… Ren admitted inwardly. If I had fought Father before. I would have been overwhelmed instantly.
His grip tightened around his katana.
Right now, I have to fight with everything I have.
Ren flashed forward, his body cutting through the air with explosive speed.
His blade descended in a full-powered strike.
Blocked.
Zenkai stopped it with minimal movement.
The impact thundered outward, but Zenkai's stance did not shift even an inch.
"You've become stronger since the last battle I watched," Zenkai said calmly. "Your power, your ability, your strength… even your techniques have improved."
Ren pushed harder, pouring more shadow into his blade.
"But right now," Zenkai continued, eyes unwavering, "you are still no match for me."
Ren struck again—faster this time.
Zenkai stepped slightly to the side and grabbed the katana from the flat edge of the blade itself.
Not the handle.
The blade.
Yume's eyes widened.
How is he holding that?!
But Zenkai's fingers weren't resisting the weapon's power.
They were disrupting its flow.
The shadow energy flickered at the point of contact.
Zenkai's leg moved instantly, sweeping into Ren's stance and striking the precise joint of his knee armor. The balance of Ren's entire body shifted in that single moment.
Before Ren could correct himself—
A second strike landed.
Zenkai's kick hit Ren's side with full force, targeting the weakened seam created by the imbalance.
Ren's grip loosened.
The katana slipped from his hand.
Zenkai caught it mid-air.
"This weapon of yours…" Zenkai said, examining it briefly. "It is well forged."
He tightened his grip—not with brute strength, but with control.
Shadow energy began unraveling.
The blade disintegrated.
Not shattered.
Unraveled—its energy dispersed and released back into the air.
Ren froze.
That wasn't raw power.
That was mastery.
The shadow fragments drifted away like black dust.
The battlefield fell silent.
Ren's armor dissolved, and he returned to his normal form.
"I lose this fight."
His voice was steady.
Zenkai raised an eyebrow. "Come on, Ren. We haven't even started properly."
Ren shook his head.
"No, Father. At eighty percent of my power… even with the power I get from the black heart, I still cannot defeat you."
There was no frustration in his tone.
Only calculation.
Zenkai crossed his arms.
"How much of the Black Heart did you truly use?"
Ren paused, thinking carefully.
"After merging with it, I never used its full power. Against Sivrath, I used only twenty percent—to finish him. After that, I restrained it."
Zenkai's expression sharpened.
"You're an idiot."
The word was blunt—but not cruel.
"You possess a source of amplification beyond ordinary monarchs, yet you hesitate to embrace it. Your eighty percent right now is incomplete. If you cannot defeat an old man like me, how do you expect to protect the people you care about?"
Ren said nothing.
Behind them, Master Kuro stepped forward.
"Ren."
His voice was calm but heavy.
"This fight with your father didn't even last a minute. Think about that. What if a real threat appears without warning?"
Ren's eyes flickered slightly.
Kuro continued.
"It has only been one and a half weeks since your battle with the shadow demons. Do you truly believe the Demon King will remain silent?"
The wind shifted.
"He is quiet now because he is unprepared," Kuro said. "But if he attacks you at this very moment…"
Ren felt a sudden chill run through his spine.
"You might not be able to stop him. Even at one hundred percent."
The weight of those words settled deeply.
A monarch… even at full power… might not defeat him.
But that does not mean he is immortal, Kuro added firmly. The point is not fear. The point is growth.
"Become stronger," Kuro said. "Strong enough to surpass even him."
Ren lowered his head.
The shattered fragments of his disintegrated katana were still dissolving into the air like fading embers.
His chest rose and fell—not from exhaustion, but from realization.
He had power.
But not mastery.
And that difference had ended the fight before it truly began.
Silence lingered across the field long after the shadows faded.
Yume's fists were clenched so tightly that her knuckles had turned pale. Daiki swallowed hard, still trying to process what he had witnessed. Even Zenkai's ancient armor slowly dissolved as he returned to his normal form, his expression calm but thoughtful.
Ren remained still for a moment.
Then he spoke quietly.
"…I was satisfied."
Everyone looked at him.
"I thought defeating Sivrath was enough. I thought forming alliances meant I was finally standing on equal ground with kings."
His gaze drifted to his right hand—the same hand that had once trembled when he was nothing more than an F-Rank.
"But I was wrong."
Zenkai stepped forward, his voice steady.
"Strength is not measured by victory alone. It is measured by what you can protect… and what you are willing to sacrifice."
Ren nodded slowly.
He understood now.
Raw power without control was unstable. A title without mastery was hollow.
Master Kuro crossed his arms.
"Your foundation is strong. Your instincts are sharp. But your control is incomplete. The Black Heart is not simply power—it is amplification. It multiplies what you already are."
Ren's eyes narrowed slightly.
"So if my base is unstable… even one hundred percent won't matter."
"Exactly," Kuro replied. "If your core lacks discipline, amplification will only magnify your flaws."
Yume stepped forward, looking between them.
"Then what do we do?"
Ren looked at her.
"We train."
There was no hesitation in his voice this time.
No pride.
No doubt.
Only resolve.
The Next Day
Morning sunlight spilled across the training grounds as Ren and the others resumed practice.
The air still carried the weight of yesterday's lesson.
Ren focused on shadow compression drills—forcing the energy to circulate through his body without overflowing. Each attempt required precision. Each mistake caused backlash.
Yume practiced stabilizing the unfamiliar energy within her core. Silver currents flickered around her fingers, unstable but growing steadier with each breath.
Zenkai observed silently.
Kuro corrected their stances without mercy.
Then—
A distortion formed in the air.
A gate opened.
Not violently.
Not chaotically.
It unfolded with controlled precision, as though space itself had been sliced carefully.
A tall figure stepped through.
White and silver robes flowed behind him. His presence was calm, refined—yet there was a sharpness in the air around him, like the edge of an unseen blade.
"It's been a while since we last met," the man said.
Ren turned, and a small smile appeared on his face.
"It has."
The gate sealed behind the figure with a soft hum.
"So," Ren continued, "the Winged King sent you."
The man nodded. "You are correct. I was sent to train Lady Yume."
Yume, Kuro, and Zenkai approached.
Ren gestured toward him.
"Everyone, this is Theron. He helped me when I was in the Winged Realm. He will be guiding Yume's training."
The man inclined his head slightly.
"I am Theron. And I am here to train Lady Yume the winged queen."
Yume stepped forward and bowed respectfully.
"Thank you, Mr. Theron. It is an honor to meet you. I am ready to learn."
Theron studied her for a moment.
His gaze was not dismissive.
It was analytical.
"The power within you is weak," he said calmly. "But not that much weak.
TO BE CONTINUED…