Demon Lord reborn as The Hero's Child

Kōya moved.

The ruined chamber violently exploded.

His suffocating Demonic Aura erupted from his body in a massive column.

Zeref barely had time to raise Stormfront.

Kōya’s heavy Hero Sword struck.

The collision produced a kinetic shockwave that tore through the remaining stone walls and blew out every remaining window in the fortress.

Zeref was thrown backward through the air. He spread his massive wings to stabilize his flight.

Kōya relentlessly followed him into the sky.

He launched himself from the shattered floor. He bounced off a falling pillar, then from a broken stone arch. His physical body became a high-speed projectile moving flawlessly through the falling architecture.

Zeref rose higher toward the storm. Searing lightning gathered around him. A massive spear of pure thunder formed rapidly in his hand.

Kōya saw it forming.

This time, he did not even attempt to retreat.

Viscous Demonic Aura heavily compressed around his right arm. Pure golden Heroic Mana flowed into the Hero Sword in his left.

The two catastrophic powers remained distinctly separate, yet they moved in perfect, lethal harmony.

Zeref descended rapidly.

Kōya launched himself upward on an intercept vector.

The Thunder Spear came crashing down.

Kōya met it head-on.

The resulting explosion swallowed the upper chamber of the Lair.

Ancient stone vanished into dust. Freezing rain instantly flashed into scalding steam. Uncontrolled lightning tore erratically through the remaining walls.

Kōya’s body was thrown downward by the backlash.

He struck a stone pillar incredibly hard. His right shoulder screamed in agony, the bone fracturing.

He caught the rough stone with one hand. His boots found purchase on the sheer wall. He pushed off, redirecting his momentum, and flew across the smoky chamber.

Zeref emerged from the blinding explosion.

Kōya struck him.

Once. Twice. Three brutal, concussive times.

Zeref barely blocked the fourth strike. Stormfront caught the Hero Sword in a grinding lock.

Zeref drove an armored kick directly into Kōya’s chest.

Kōya crashed through a heavy stone balcony, tumbling through the debris. He rolled to his feet. Thick, dark blood ran freely from the corner of his mouth.

Zeref descended slowly through the smoke. ”You cannot possibly win this.”

Kōya stood perfectly straight.

Zeref raised Stormfront. ”You are completely exhausted.”

Kōya wiped the blood away with the back of his hand.

”You are heavily injured.”

Kōya steadily raised the glowing Hero Sword.

”You are fighting inside my storm.”

Kōya looked up at him, his dual-lit eyes burning. ”And you are fighting inside my anger.”

Zeref’s arrogant expression finally hardened into genuine concern.

Lightning struck the ground between them.

Kōya disappeared into the blinding explosion.

Zeref smiled, expecting to see a corpse.

Then, golden light emerged from the thick smoke.

Kōya stepped smoothly through the inferno. The massive Hero Sword cut in a devastating downward arc.

Zeref barely blocked in time. The floor beneath him shattered under the pressure.

Kōya immediately released a massive burst of Demonic Aura directly from his right side.

The localized pressure wave drove Zeref backward.

Zeref’s wings snapped open. He attempted to escape upward into the storm.

Kōya grabbed a hanging iron chain, wrapped it securely around his right arm, and pulled with monstrous demonic strength.

The rusted chain snapped tight around one of the high, ruined towers.

Kōya launched himself upward, using the chain as a pivot. The architecture itself became an extension of his wrath.

Zeref turned to track him.

Kōya came screaming up from the blind spot below.

Hero Sword. A massive upward slash.

Zeref frantically blocked.

Kōya twisted his body mid-air. Demonic Aura burst explosively from his right shoulder. His physical trajectory changed completely.

He struck brutally from the exact opposite side.

Zeref barely avoided decapitation, the blade slicing his shoulder guard.

Kōya landed heavily on the upper tier. Zeref landed violently opposite him.

For the first time in the engagement, fresh, dark blood covered both of them.

Zeref’s chest heaved. Kōya’s battered body was barely holding itself together through sheer force of will.

Neither warrior moved.

Then, Zeref actually laughed. A wet, ragged sound.

”You really are his son.”

Kōya looked at him coldly. ”Whose?”

”Seiya’s.”

Kōya’s expression hardened.

”You knew my father too,” Kōya stated.

”Everyone in the upper echelons knew the great Hero.” Zeref slowly raised the crackling Stormfront. ”But your foolish father never truly understood what absolute power was.”

”My father understood more than enough.”

”He died in the mud.”

”So did Yuna.”

Zeref froze at the mention of the name.

Kōya took one slow, deliberate step forward.

”And you were there for both of them.”

Zeref’s cruel smile vanished.

Kōya’s golden aura flared brilliantly. ”You personally killed her parents.”

Another heavy step.

”You cursed a child.”

Another step.

”You sat back and watched her suffer for years.” ℯℯ𝘭.

Another.

”You watched her grow into a warrior.”

Another.

”You patiently waited for her to become tactically useful to you.”

The raging storm above began roaring again, matching his rising cadence.

”And then you took her life.”

Zeref raised Stormfront in a high guard. ”Yes.”

Kōya stopped walking.

His dual-lit eyes became completely, terrifyingly empty.

Then, his aura exploded.

There was no dramatic roar. No primal scream. No theatrical declaration of vengeance.

The apocalyptic pressure simply arrived.

The entire ancient Hero’s Lair trembled down to its bedrock. Massive cracks raced across the stone walls. The air pressure blew the freezing rain back, stopping it from falling inside the chamber.

Nearby, lesser demons lurking in the shadows collapsed. Some dropped their weapons in sheer terror. Others could not even remain conscious under the weight.

The violet-black Demonic Aura surrounding Kōya expanded, filling the hall.

But this time, it carried something older than condensed Demonic Mana. Something unimaginably ancient that had been patiently sleeping beneath Kōya’s human emotions.

The absolute pressure of total destruction.

The terrifying, unquestionable authority of a true Demon Lord.

Zeref’s red eyes widened in horror. ”That aura...”

Kōya slowly raised his head.

Pure golden Heroic Power burned brilliantly around his left side. Viscous, violet-black Demonic Aura burned with apocalyptic heat around his right.

Neither catastrophic power consumed the other. Both answered his will.

Zeref took an involuntary step backward.

For the first time in his long, bloody existence, the Lightning Demon Peer looked afraid.

Kōya walked slowly forward.

”I do not care what you are.”

The heavy Hero Sword rose into a guard.

”I do not care how many centuries you have lived.”

Stormfront crackled nervously in Zeref’s hand.

”I do not care how powerful you arrogant bastards think you are.”

Kōya’s dual-lit eyes locked onto Zeref’s terrified face.

”You stole her future.”

His voice was quiet, yet it deafened the thunder.

”You stole her family.”

Another slow step.

”You stole her life.”

The massive Hero Sword ignited with blinding golden light.

”And you arrogantly thought you could turn everything she was into something you could consume.”

Kōya raised the massive sword high above his head.

”I will not let you take anything else.”

Zeref screamed, a sound of pure desperation. Blinding lightning exploded across the chamber. He launched himself forward.

Kōya did the exact same.

Their legendary weapons collided with catastrophic force.

The resulting shockwave ripped through the remaining foundations of the Lair.

Zeref attacked desperately from above. Kōya flawlessly blocked. Lightning struck. Kōya redirected it. Zeref spun. Kōya ducked.

Stormfront came crashing down. Hero Sword rose to meet it.

Steel met legendary steel. Searing lightning met suffocating Demonic Aura.

Pure golden Heroic Power cut cleanly through the storm.

Kōya stepped aggressively forward, driving the offensive.

One brutal strike. Zeref barely blocked.

Second strike. Blocked, the demon staggering.

Third strike.

Stormfront screamed under the impact, lightning surging violently along its intact blade.

Zeref’s eyes widened in sheer disbelief.

Kōya struck again with devastating force.

The legendary lightning blade released a violent burst of blue lightning, but remained completely intact in Zeref’s grip.

Zeref panicked, releasing a massive, point-blank burst of electrical power from Stormfront.

Kōya crossed both of his arms.

His Demonic Aura absorbed the kinetic impact. His golden Heroic Power ruthlessly pushed straight through the resulting opening.

The heavy Hero Sword struck Zeref cleanly across the chest.

The Demon Peer was thrown backward through the air. He crashed brutally into the ancient stone altar, obliterating it. Stone exploded everywhere around him.

Stormfront slipped from Zeref’s numb hand and crashed against the floor, still crackling with blue lightning.

Zeref desperately tried to stand, slipping in his own blood.

Kōya walked slowly, relentlessly toward him.

Thick black blood covered almost the entirety of Zeref’s body. The broken Demon Peer looked down at the glowing Hero Sword. Then up at Kōya.

”You...” He coughed violently, spitting blood. ”You shouldn’t be physically able to...”

Kōya stopped a few paces away.

Zeref’s terrified eyes moved frantically between the blinding golden light and the suffocating violet-black aura.

”Hero... Demon...”

Kōya said nothing.

Zeref’s expression became pathetically confused. ”How can both exist...”

Kōya answered him quietly.

”Because neither one of them owns me.”

He slowly raised the massive sword.

Zeref desperately attempted to move.

Too late.

The glowing Hero Sword pierced flawlessly through the remaining storm, driving cleanly through the Demon Peer’s chest and pinning him to the ruined stone floor.

Blinding golden light erupted violently from the wound.

Zeref’s body froze.

For one single instant, the chaotic chamber became deathly silent.

Then, the ambient lightning vanished entirely from the Lair.

Stormfront lay on the floor, its blade still alive without the blue lightning.

Zeref looked down slowly at the holy blade protruding from his chest.

His physical body began breaking apart, dissolving rapidly into thousands of dark fragments of Demonic Mana.

Kōya brutally pulled the Hero Sword free.

Zeref staggered, falling to his knees. His dying red eyes remained fixed entirely on Kōya.

”So this...” His voice weakened into a rattling rasp. ”This is exactly what she left behind to destroy me.”

Kōya lowered the golden sword.

”No.”

Zeref looked up at him.

Kōya’s cold expression did not change an inch.

”This is exactly what she willingly gave me.”

Zeref’s physical body continued rapidly dissolving.

The remaining, highly concentrated Demonic essence began aggressively gathering in the air.

The empty crystal resting on the ruined altar suddenly responded. Dark, volatile energy flowed toward it.

Kōya looked over sharply.

The crystal began ominously glowing with a dark light. Zeref’s remaining power was being violently drawn inside the vessel.

But something else entirely unexpected happened.

Images began to rapidly appear within the dark stone. Fragmented flashes flickered.

A clawed hand. A long, dark stone corridor. A glowing, intricate ring. A harsh command. A sprawling, bloody battlefield. A terrified woman surrounded by dark crystals. A massive Demon army retreating.

Then, everything abruptly disappeared.

Kōya stared at the pulsing crystal. ”What was that?”

Zeref was almost entirely gone now. His ancient face was incredibly difficult to see through the dissolving darkness.

Kōya looked back down at the dying demon. ”Tell me.”

Zeref’s final expression fundamentally changed. It wasn’t fear of death or lingering anger. It was something closer to profound confusion.

”I...” His voice faded almost to nothing. ”There is...”

The crystal violently pulsed again.

More Demonic Mana was ripped from his fading body.

Zeref’s remaining physical form broke apart completely.

Kōya reached desperately toward him. ”What is there?!”

Zeref’s final, echoing words were barely audible over the rain.

”More.”

Then, the Lightning Demon Peer vanished from the world.

The crystal absorbed the very last of his remaining dark essence.

Kōya’s eyes shifted toward Stormfront.

The legendary Lightning Sword still lay intact among the ruined stone, its blue lightning already faded away.

Absolute silence returned to the ruined Hero’s Lair.

Only the sound of the freezing rain remained.

Kōya stood completely alone among the smoking ruins.

Stormfront lay nearby, still intact. The legendary Lightning Sword that had once belonged to Zeref now awaited a new wielder.

His heavy sword hung loosely at his side. His right hand still radiated a violent Demonic Aura. His left hand still burned with Yuna’s pure Heroic Power.

He did not move a single muscle for several long seconds.

Then, he slowly looked toward the darkened, pulsing crystal on the altar.

Images flickered inside it again.

But this time, they did not disappear immediately. They stabilized.

A much younger Zeref stood in a long, dark stone corridor. An intricate communication seal glowed brightly in his armored hand. A commanding voice spoke from somewhere beyond the boundaries of the memory.

Zeref turned. He listened carefully. Then, he answered.

Kōya stepped cautiously closer to the altar.

The image inside the crystal sharpened perfectly. The memory was fully opening.

This memory belonged to Zeref’s dark history, connecting Yuna’s fate to the larger continent-spanning Demon operation.

Kōya stared deeply into the dark crystal.

The next vital memory began to play.