"Sir, what should we do?"
One of the subordinates cried out as a tide of Cursed Spirits poured from the treeline, bashing against the translucent wall of the barrier.
These sorcerers were the frontline guards of the Kinki region, seasoned men suddenly made to feel like children as a sickening amount of cursed energy enveloped the vicinity with its malice.
"Keep those damn balls within you!"
The leader's stern voice resounded, but his face told a different story. His eyes were wide, reflecting the twisted, multi-limbed horrors screeching just inches from his nose.
Tengen's barrier, the ancient protective measure designed to envelop Japan, was groaning under the weight. Usually, it filtered the world's resentment, but today, the rampant generation of spirits had turned the fiasco deadly.
"Did Nobuaki report this back? We need urgent help here!" The leader barked, looking at his subordinate.
"I'm sure he did! It's just... the interference is everywhere!" The subordinate shouted back, trying to boost their morale despite his hands trembling around his focus charm.
"Keep the line, huh... So be it," the leader muttered.
This was the reality of the Jujutsu world. A life of living behind the scenes, unappreciated, severely overworked, and often ending in a nameless grave.
"RAAAAAHHHH!"
A roar that sounded like grinding metal tore through the air. A massive Grade 1 Cursed Spirit, a mountain of bloated muscle and weeping eyes, bashed its head into the barrier.
"Shit! Brace yourselves!" the leader commanded.
Bang!
Bang!
Bang!
Each impact made the transparent barrier shake, sending ripples of trepidation through the men inside.
Fine, spider-web cracks began to crawl across the air.
"Are we going to die?!" One of the subordinates felt a wave of grief wash over him, his spirit breaking before the glass even did.
"SHUT UP!" The leader cried out in alarm, but it was too late.
CRACK!
"DAMMIT!"
A frantic curse escaped the leader's mouth as the barrier shattered like a glass dropped into the ground.
The scene was a hell on earth; with the dam broken, the march of Cursed Spirits poured forth in a flood of teeth and spite.
The sorcerers fought relentlessly, their Cursed Energy flared out like a light, but their spirits were failing too hard.
"Am I late to the party?"
As the sorcerers were enveloped in this quagmire and losing their sanity, a voice cut through the screeching of the damned.
It was a childish tone, yet there was a terrifying hint of confidence buried within it.
A sharp side-eye was directed by the leader toward a thick branch nearby, even as he was occupied by a cluster of monsters. A child sat there, perched like a delinquent, looking down at the carnage with bored, golden eyes.
"What the hell is a brat doing here?! Get back!"
The leader grimaced, his mind racing.
Was this supposed to be reinforcement?
A massive amount of Cursed Energy was felt radiating from the child. For a slight second, a flicker of hope was seen until he shook his head in despair.
Monstrous reserves didn't matter against a tide this thick, especially with two Grade 1 spirits and a hidden leader in the back who hadn't even made a move.
On the other hand, Yoichi's golden eyes were scanning the field with a grin. He ignored the small fries as his gaze locked onto the "hidden" boss.
The energy pervading the atmosphere was suffocating, turning the sunlight into a sickly violet.
This energy... it's somewhat familiar.
The earth shook violently as the silhouette of the boss became evident. Each step squashed multiple weaker cursed spirits in its wake, the behemoth baring no mercy for subordinates it deemed unworthy of its presence.
"HALF-BLOOD!"
A roar erupted, sending waves of pressurized air that shook the trees to their roots.
Some of the weaker spirits simply disintegrated under the sheer volume of the roar. Destruction was wreaked upon the environment, turning the serene forest into a splintered graveyard.
"Demonic Energy..."
A frown appeared through Yoichi's face as he recognized this particular hellish frequency.
But the frown didn't last long.
Soon, his mouth curled upward as he elegantly jumped into the air, his white coat flapping like the wings of a freedom eagle.
Many questions appeared in his mind, yet the thrill of the hunt made him smile.
Things were finally getting interesting.
"Hahaha! It's showtime!"
In the air, Yoichi hoisted the two handguns.
A rain of magically infused bullets was unleashed, wreaking havoc on the front lines of the march.
Without any restrictions, he brought Demonic Energy into the play. Each bullet left craters in the earth as the kinetic force became multiplied by the hellish output of the twin pistols.
While Yoichi could use Cursed Energy as a fuel source for his Devil Arms, the effect had always felt inadequate—like running a supercar on low-grade kerosene. Now, with the real deal flowing through his veins, each cursed spirit struck by the bullets simply exploded into a mist of purple vapor.
When he finally landed on the ground, the impact sent a tremor through the soil, and Rebellion was unleashed from its slumber with crimson light in those hollow eye sockets.
A sudden burst of speed propelled Yoichi forward like a rocket, the tip of his blade gathering a concentrated point of energy that bored straight through the chest of a Grade 1 spirit.
Before the creature could even dissipate, he transitioned the momentum.
The air was filled with a blurring flurry of thrusts, so fast that the blade seemed to exist in ten places at once. The sound was a consecutive percussive thrum-thrum-thrum as he turned the front line of the horde into Swiss cheese.
A savage, elegant sequence of swings followed.
Yoichi spun with the Rebellion like a playground, his school coat flaring out as he carved a path of destruction through the ranks.
Each skillset proved to be lethal; the cursed spirits reacted by launching a desperate, simultaneous assault, but they were simply throwing themselves into a meat grinder.
The sorcerers stood frozen, their weapons lowered as they were stupefied by this dazzling "performance."
"Is... is he even human?" One of the subordinates stammered, his eyes tracking the purple-gold trail left by the boy's blade.
"Who cares?!" The leader barked, though his own jaw was slack. "Just stay out of his way!"
"Hahaha! Let's rock!"
A wild cry escaped from Yoichi's mouth as he materialized a sleek, purple guitar.
Once the first chord was struck, the sky turned a bruised violet, sparkling with discharge that electrified the very oxygen in the atmosphere.
With electrifying performance cranked to the limit, the disgusting smell of charred flesh permeated the forest; each chorus sent waves of high-voltage power through the ground, turning the lower-level spirits into ash before they could even scream.
"Look! Is he Gakuganji-sama's student? I wonder what's his relation to our principal?"
"Not good! Kid, be care—"
However, as the leader began to speak, the hidden boss moved. The behemoth defied physics, its gigantic frame blurring with an unparalleled speed that left a vacuum in its wake.
A smothering shadow of a spiked club appeared over Yoichi. The boy, currently kneeling while rocking his guitar, didn't flinch.
Instead, a knowing smile appeared through his face.
Bang!
A terrifying crater exploded into the earth, the impact of the building-sized club sending shockwaves that knocked the standing sorcerers off their feet.
Dust filled the clearing, thick and choking.
As the grit settled, the boss's silhouette became terrifyingly clear. It possessed a snarling, dog-like head crowned with two jagged horns, its massive form stuffed into an oversized suit.
It was an Oni, but not one birthed from human fear alone. It was something older, something darker.
A wave of dismay washed over the sorcerers, many bowing their heads in the grim belief that the child had been pulverized. But then, a voice appeared once again, cutting through the settle of the debris.
"A little bit angry, aren't we? Why not savor the music?"
A collective gasp was heard as the leader looked up. Yoichi was perched casually on the Oni's massive shoulder, looking chilling and relaxed with Rebellion resting against his own shoulder.
At this point, a cold realization began to settle in Yoichi's gut.
This wasn't a curse born from the rumors of Kyoto.
Must've been that damn god's plot twist!
This isn't the Jujutsu Kaisen that I know!
This was a crossover from a hell he knew all too well.
_________________
For those who were wondering why I did include this, it's a bit of a risk for me to add this since it will completely negate the feats of Sukuna and Gojo as these Yokai appeared right now.
What is a Yokai? They are supernatural phenomena that appeared through myths, word of mouths, and folklore. I was thinking that if I wanted to delve in the supernatural section, then let's add something to the table instead of being overpowered with 80% or 90% of the next chapters becoming Slice of Life.
And also, it was connected to Yoichi's emergence since these things energy output was Demonic Energy, not Cursed Energy. I also wanted to think what if Sukuna used his Heian Era with a Yokai Vessel against Gojo and the rest of the casts.
I know it will be a risk for me to do this since it was overkill against Gojo, but I wanted to spin it off instead of another boring JJK Fanfiction.
Also, Yokai is from Japan so you know I mean.