Seven days before untold destruction. 

It started with a chance meeting.

In all the time he’d spent on Earth, navigating its supernatural currents ruled by gods and spirits alike, adapting to a world fundamentally weaker than Yggdrasil yet infinitely more chaotic, Sekai did not expect to befriend a godling.

She was small—far too young to bear the weight of divinity. Her power, barely formed, flickered like an ember caught between being snuffed out or bursting into flame. She had stumbled into him quite literally, nearly collapsing as he caught her in his arms. 

That was his first glimpse of Tsukuyomi Mei. 

A young shinto deity, born from the prayers of a small shrine barely clinging to existence in modern Tokyo. She looked lost, scared, maybe uncertain of what she even was. 

And for reasons Sekai never fully understood, he stayed with her.

Maybe it was because she reminded him of something he’d lost. 

Maybe, it was because, for the first time since he’d arrived in this lesser world, someone had looked at him not with fear or reverence, but with trust.

“Look, Sekai! I did it!” Mei’s voice was filled with pure joy, her small hands outstretched as a floating orb of moonlight danced around her fingertips. She beamed up at him, eyes glowing silver beneath the night sky.

Sekai had never intended to become her teacher.

Mei was so naive then, so trusting. She followed him like a shadow, demanding to learn spells far beyond her reach, convinced that if she grew stronger, she could carve a place for herself among the gods.

“You’re a fast learner,” he said, feigning indifference.

“That’s because I have the best teacher!” she responded, her laughter bright, her trust absolute.

It was… nice.

To matter to someone again, to be something other than a ghost of Yggdrasil’s past. 

And for a time—he let himself believe that this fragile happiness could last.

Five days before the cataclysm, it started slowly. 

Mei was growing stronger, her divine power stabilizing under his guidance. She was so proud, so eager to prove herself—to him, the world, and the gods who’d abandoned her. 

But power always came at a cost.

Unseen cosmic forces and untold magic began to shift around them, reacting not to her presence—but to his. 

Sekai ignored the warnings at first. The shadows curling around his magic; the way the world itself seemed to flinch away from him.

“Sekai? Your aura… It feels different.” 

Mei noticed before he had.

Her expression was hesitant, confused—but not afraid.

Never afraid.

“It’s nothing,” he told her.

“Are you sure?”

“Of course.”

Lies.

The whispers started not long after. 

“She trusts you, doesn’t she?”

“She would follow you anywhere.”

“And yet… the gods did nothing for her. Still, they turn their backs on her existence.” 

“You could change that.” 

Sekai told himself that those were just the serpent’s lies; the endless, poisoned voice of a lost snake, bound within him, seeking a crack within his resolve.

But deep down, he already knew the truth.

He was already listening.

Three days before the ultimatum.

It was raining on that fateful night.

Natural forces rejected him entirely, the world itself shifted away from his presence. The corruption that once whispered became something real, and it burned beneath his skin like a hunger that could not be sated. 

And yet, Mei came to find him.

She reached for him.

And he let her.

Her fingers were warm against his face, grounding him, reminding him that there was still something human inside him. 

“You’re changing.”

He closed his eyes. “I know.”

“Then fight it!” she pleaded. 

And for a moment—just a fleeting moment—he wanted to. 

But the hunger already took root. 

The natural forces of the world screamed as his power surged, a darkness that was no longer his own, a power that had been festering inside him for far too long. It was as though ancient choirs began to sing and praise his name.

And the serpent whispered:

“She is the answer.”

“She is power.”

“She is divinity.”

“And she belongs to you.”

Sekai moved before he could stop himself.

Mei barely had time to react as his fingers closed around her throat. His magic pierced into her soul, consuming her divine essence before she even had the chance to scream. 

Her silver eyes widened in disbelief, her small hands grasping at his wrist—not to fight, but to understand. 

“S-Sekai…?”

Her voice cracked, weak, fragile—like her fading presence.

It was… easy.

Too easy to consume her.

Her body crumpled against his chest, her form dissolving into raw, shimmering energy, feeding the ever-hungry serpent that wrapped itself around his soul. 

And Kisaragi Sekai, the Magic Caster, the Guildmaster, her mentor—did nothing to stop it.

Because somewhere along the way, he’d stopped being himself. 

When the last trace of Tsukuyomi Mei vanished into his magic, her warmth fading from existence, leaving nothing behind—

Sekai finally realized what he became as a low sadistic chuckle manifested, synchronized with the serpent within, Nidhoggr's own laughter.

“My dear Sekai… Welcome home.”

Since the death of the young deity, Sekai wasted no time to put his new agenda into action. 

The streets of Tokyo were painted in divine carnage. 

The scent of mystical flames and burning ley lines filled the air, the sky itself twisting under the sheer weight of corruption as reality warped around Kisaragi Sekai. His golden eyes shined with malicious intent, flickering with traces of a sadistic darkness. Nidhoggr’s influence had consumed him completely.

Lesser gods, spirits, and celestial entities who had once claimed dominion over these lands fled in terror. Some tried to fight, but it was pointless.

They were nothing more than prey now.

“Run. Scream. Beg.”

The serpent’s voice slithered through his mind, no longer an unwelcome guest but a permanent fixture—his companion, his truth.

“It doesn’t matter. You will devour them all the same.”

And he did.

A shrine guardian, an old fox spirit that once watched over a forgotten temple, fell first. 

Her body burned away, the sacred sigils meant to protect her shattered like fragile glass under the weight of his magic.

He drank her power in a single breath.

Another—a young wind deity, too slow to escape—was caught in his grasp, his divine essence siphoned from his very soul before his body crumbled into dust.

Sekai barely felt it anymore. 

There was no hesitation.

No remorse.

Just hunger.

In a twisted sense of fate, the serpent’s whispers made him believe the gods had taken from him. Stole from him.

Now, he would consume them all.

They did not deserve their divinity.

Only he did.

His hands trembled as another burst of divine energy flowed into him, the once-sacred power twisting, corrupting, turning into something greater than it had ever meant to be.

The sky was torn asunder, the storm of his devastation raging across Tokyo.

Lightning tore through the heavens, shadows bled into existence, the balance of power unraveling from every life he stole.

But it wasn’t enough.

His insatiable hunger for divine power was a bottomless pit that urged for more, and he readily listened.. 

Over the next two days, the city of Tokyo burned with corrupted flames, turning sacred shrines and spiritual energies into ash and ruin.

The prey he sought became more than mere local deities. Such small powers were nothing but an appetizer of the feast to come, he aimed for higher, more delectable prey. 

The first on the main course was Fūjin, the god of wind. 

He descended with a wrathful storm, his emerald skin glowing, his sacred bag of winds tearing apart the city in an attempt to contain the corruption.

But the moment he stepped too close to Sekai—his fate was sealed. 

The magic caster reached into the storm itself, gripping the very essence of the wind god’s existence, and crushed it in his grasp.

Fūjin’s divine form shattered, his celestial screams lost to the howling storm as his divinity was drained, absorbed, and reduced to nothing. 

The winds that once carried the breath of the world fell silent.

The next to fall was Benzaiten, the goddess of wisdom and music. 

She wielded a radiant biwa, her voice was hailed by scriptures as a melody that could cleanse corruption, restore purity, and halt madness.

She believed she could reach him.

“Kisaragi Sekai!” she called, her voice ringing like a bell through the ruined streets. “You are more than this! You are not a beast—you can still turn back!”

For a moment, he paused.

She sounded almost like Mei.

But then, Nidhoggr whispered.

“She seeks to take from you.”

“She wishes to steal your power, to undo what is rightfully yours.”

“Do not listen. Devour her.”

And he obeyed.

A single flick of his wrist, and shadows erupted from the ground, forming chains of pure void, wrapping around Benzaiten’s throat, wrists, and legs.

Her sacred music choked in her throat as the chains dragged her forward, her radiance withering beneath the weight of his curse.

Her golden biwa splintered into dust as her body collapsed against his chest, her form trembling as her divinity was siphoned away, piece by piece.

She whispered something—a prayer, perhaps—before she finally ceased to exist. 

The sound of music in the heavens soon fell silent with her death. 

The next to fall before the rising sun could light the dawn of a new day, was the thunder god, Raijin. 

His drums of war roared across the sky, bolts of lightning flashing like celestial blades, seeking to strike him down, and pierce through the corruption that had become Sekai’s very essence.

“You defiled balance! You defile the gods!” Raijin bellowed, his divine presence crackling with fury and judgement. “I will not let you stand!” 

Sekai laughed.

It was a twisted sound, like something wrong; something that had no place in this world. 

He stepped through the lightning, his body untouched by divine retribution. 

And then—he reached out.

Raijin never even touched the ground again. 

Sekai tore him from the sky, his fingers digging into the thunder god’s chest. His magic wrapped around Raijin’s divine heart like a serpent coiling around prey, before crushing its existence into nothing.

The god screamed, a sound that shook the very clouds above.

But it was already over. 

The drums of thunder stopped.

The skies above grew eerily quiet.

And Raijin—one of the great storm deities of Japan—was gone.

Erased.

Devoured.

Sekai’s chest heaved heavily as he exhaled with ragged breaths. His body trembled not from exhaustion—but from the sheer power coursing through his veins.

Around him, the world around him continued to change. The storm of corruption raged unchecked, twisting the sky into an abyssal vortex.

The once-sacred ley lines; the natural forces of the world had been fractured and corrupted beyond recognition, its divine energy now blackened and twisted, spiraling into a vortex of decay.

Tokyo, once vibrant with the presence of spirits, gods, and celestial forces, had become a wasteland of slaughtered divinities. The air was thick, as if the essence of fallen gods refused to disappear and move on.

The scent of annihilation permeated everything; a carnage that unrivaled any other.

Sekai knew that he became unstoppable; something beyond the gods themselves.

But still—it wasn’t enough.

The divine power he’d consumed, the essence of Fūjin, Benzaiten, Raijin, and countless minor deities before them, had only whetted his never-ending appetite.

He needed more. He deserved more.

Then, everything came to a sudden halt.

A pulse of power.

A single, unshakable presence had entered the battlefield. 

Waves of ethereal energy spilled forth, their hues shifting between shimmering blues, radiant violets, and streaks of icy white, radiating with the sheer force of celestial authority. The very fabric of reality trembled, bending beneath the weight of something far greater than any god yet far more terrifying than any beast.

Seiryū has arrived.

He floated before Sekai, adorned in his battle armor, its deep sapphire hue glinting under the shattered moonlight. Dark, polished plates lined with a gold trim covered his form, regal yet exuding a presence of overwhelming dominance. A flowing cape, edged in golden embroidery, swept behind him with the latent force of his power.

But it was his aura that flickered—not in rage, but in something uncertain; something unsteady.

Unlike the chaos that Sekai had unleashed, Seiryū‘s power radiated in controlled, elegant waves of celestial flame—a presence that did not burn, but instead demanded absolute control over all things.

His azure horns glowed softly, his dragon tail shifting behind him, but his golden eyes—eyes that had seen centuries of war, gods that rose and fell, worlds reshaping themselves—were wide. Uncertain.

He looked upon Sekai—not as a warrior or a god, but as a man staring at something he could barely comprehend.

A friend he no longer recognized.

His throat tightened. His hands, clad in armored gauntlets, trembled slightly before he clenched them into fists.

“Kisaragi…?”

The name barely left his lips, as if saying it would somehow make sense of the horror before him.

“What… What have you done?”

It was not an accusation.

It was not anger.

It was fear.

Not of Sekai’s power. Not of the devastation he had wrought.

But fear that the man he once knew, fought beside, laughed with, and trusted—was gone.

“Tell me… tell me this isn’t real.” His breath was unsteady, his voice almost breaking. “All of them… the gods, the spirits…  Fūjin, Benzaiten, Raijin… Tell me you didn’t—tell me this isn’t what it looks like!” 

But even as he spoke, he knew.

The answer was already before him. In the ruins of Tokyo, in the silence where gods should have been, in the abyss that now filled Sekai’s serpentine irises within his golden eyes.

Sekai exhaled slowly.

The serpent within him shivered, its delight palpable.

And then, slowly—he smiled.