Hearing Tengen Uzui's grim assessment, Li Ke thought back to the image of the teenage boy turning into ash under the setting sun. He had witnessed the phenomenon but hadn't paid it much attention at the time. After all, his Observation Haki hadn't registered any lingering danger from the disappearing spirit, and they hadn't been ambushed since the kill.
With his current defensive metrics, there was truly very little for him to fear.
"And it's blindingly obvious that the native demons who fuse with these alien monsters experience an exponential surge in their baseline power," Tengen pressed on, his voice heavy.
He was completely incapable of maintaining the same level of casual relaxation as Li Ke.
The Corps had cross paths with massive, five-to-six-meter-tall alien behemoths before, but those heavy variants almost universally suffered from incredibly sluggish, predictable movement parameters. This fused spider-beast was a terrifying contradiction—it possessed absolute, hyper-velocity acceleration that borderlined on divine speed!
If the rest of the hidden entities lurking inside Mount Natagumo possessed identical combat metrics to the monstrosity they had just put down, then...
The Demon Slayer Corps would be completely wiped from the face of the earth!
In fact, human civilization itself would face absolute, unmitigated destruction!
Tengen analyzed his brief five-second engagement with the arachnid hybrid. His ninja calculator warned him that if Li Ke hadn't spearheaded the assault by unleashing that continuous torrent of azure fire to incinerate the toxic, acid-secreting bristles protecting the chassis, his own maximum physical output would have hit a wall. Even if he had willingly sacrificed his own life to force a breakthrough, he would have only managed to shear off one or two limbs before the acid dissolved his body to grease.
Under normal parameters, properly subduing a fused anomaly of that caliber would demand a minimum deployment of three synchronized Hashira!
And statistically, at least two of those Hashira would end up permanently crippled or dead before the target turned to ash!
Yet, coordinating alongside Li Ke, the entire threat matrix had been neutralized with absolute ease, with the total clock time of the brawl barely scratching five minutes. The sheer, terrifying scale of Li Ke's raw combat output was written across the scorched landscape.
Especially that fire...
Recalling the visceral wave of primal panic that had thrummed through his heart when the azure blaze flared up, Tengen's knuckles whitened as he gripped his hollow hilts. That elemental force was so obscenely dominant it naturally commanded terror; he couldn't formulate a single defensive strategy on how he would react if he were forced to face that sapphire inferno as an opponent.
He couldn't even map out a theoretical method to suppress or克制 (counter) Li Ke's flame manipulation!
It was simply too chaotic, too alien, and far too absolute!
But fortunately for humanity, this reality-bending powerhouse stood on their side of the chessboard.
"No wonder Shinobu chose to..." Tengen muttered under his breath, a subtle realization clicking in his mind.
As battle-hardened comrades who routinely entrusted their lives to one another on the front lines, Tengen and Shinobu maintained an exceptionally solid relationship despite not operating together daily. It was a pure, unadulterated bond forged between soldiers—two driven colleagues sacrificing everything to achieve a singular, monumental objective.
This ironclad loyalty was the defining trait of the Demon Slayer Corps. The vast majority of their elite roster possessed remarkably pure, straightforward motives; when it came to holding the line against monsters threatening human existence, they were easily the most trustworthy individuals on the planet.
Of course, human nature dictated that traitors would occasionally rot their foundations from within—that was simply an unavoidable administrative hazard.
Furthermore, Tengen was a professional shinobi master, operating at a level of tradecraft that made a modern tournament fighter like Mai Shiranui look like an amateur. Reading microscopic cues and body language was a rudimentary, baseline skill in his repertoire; he could explicitly discern the overlapping pheromones and blended physical signatures currently lingering over Li Ke and Shinobu Kocho. He didn't even need to waste a single brain cell guessing what had transpired behind closed doors.
Initially, he had harbored a lingering worry that Shinobu was simply spiraling out of control due to her recent emotional depression—believing her lack of raw physical power made her obsolete, leading her to make a reckless, self-destructive choice. But analyzing the layout now, a different tactical truth clicked: Shinobu was deliberately leveraging her own womanhood to firmly bind this interdimensional powerhouse to the human cause.
While the raw reality of the arrangement was slightly awkward to acknowledge, Tengen understood and fully empathized with her conviction and the sheer, desperate gravity that had driven her to make that vow.
"Shinobu really went that far... But considering the catastrophic threat matrix we're looking at, I can only say you did an absolute masterclass of a job, pal."
Tengen mused internally. Turning his focus back onto their designated base camp coordinates, he processed the tactical metrics for a brief moment before locking his gaze dead-center onto Li Ke.
"What's your physical status? Are you still in prime condition to launch into another immediate engagement?"
Tengen queried with absolute, dead-pan seriousness. Li Ke offered a casual, solid nod.
"I'm completely fine. But looking at the terrain up ahead, I strongly recommend that the rest of your squad benches themselves right now."
Li Ke gestured a thumb toward the auxiliary Demon Slayer Corps members trailing behind Tengen's horse. He had been micro-analyzing the structural anomalies of the battlefield for a while now; that three-story colossal spider-fiend had continuously excreted thick streams of acidic slime and dense clusters of egg sacs across the perimeter.
More specifically, those egg sacs could dynamically split open to hatch thousands of hyper-aggressive arachnid variants, or liquefy into corrosive puddles to coat the earth. Since the massive titan spider had spent the entire fight skittering exclusively across the suspended, invisible silk lines in the canopy, that acidic ground-slime wasn't engineered to assist the giant's mobility at all—it was laid down specifically to serve as an ideal environment for the tiny hatchlings.
And worse...
Li Ke trained his advanced sensory vision toward the sectors completely choked out by the slime. Deep within those toxic zones, thousands of tiny spiders were locked in a savage, cannibalistic frenzy, tearing each other apart while bizarre, asymmetric organisms lurked amidst the muck to actively hunt the hatchlings, or be devoured by them in turn.
The visual sent a massive wave of dark, instinctual dread straight through his chest. No matter how he rationalized the layout, this structural phenomenon resembled nothing less than a living, biological creep-carpet—a deliberate, invasive zerg-like ecosystem aggressively terraforming the local geography.
He tracked the behavior of the tiny spiders with absolute precision. These anomalous arachnids could effortlessly ambush and butcher local rabbits, deer, and birds in a matter of seconds, systematically wiping out the native fauna of the mountain, while an entirely different tier of unidentifiable, grotesque bio-forms hunted the spiders themselves.
In other words, these interdimensional entities from the 7 Days to Die shard weren't just killing people—they were actively rewriting the baseline ecology of the planet!
Li Ke couldn't confirm whether this systemic terraforming was a universal trait of the invasion or an autonomous capability unique to this specific spider strain. But watching those abstract, misshapen little bio-forms wriggle through the brush, his wrist rolled fluidly, and the newly upgraded Blade of the Family flew smoothly out of its scabbard once more.
"Their baseline attributes are far too low to survive this biome," Li Ke stated, his voice cool and analytical. "Look into the deeper brush over there. The terrain is teeming with millions of tiny variations of that massive spider I just executed. If you order your standard troops to advance into a biological meat-grinder like this, they will be utterly useless. It's far better to order a total retreat for their own safety."
Li Ke executed a sweeping cleave with his greatsword, unleashing a massive volley of Firebending embers that illuminated the pitch-black canopy. The sudden illumination forcefully exposed the sheer, suffocating density of the crawling arachnid swarm to the rest of the vanguard.
As his Dragon Fire rained down onto the forest floor, it violently ignited the undergrowth, launching a rolling forest fire that aggressively incinerated the invasive creep-carpet and the distorted bio-forms nestled within the slime.
Through the burn metrics, Li Ke noted a critical relief: unlike the massive, armored ghost-king from earlier, these microscopic hatchlings didn't require high-yield Dragon Fire to clean the slate; standard, conventional elemental heat was more than enough to cook them down to ash.
"This is..."
Tengen Uzui was absolutely no fool. The horrific visual of the crawling terrain immediately shattered any lingering thoughts of a standard military deployment. The auxiliary slayers he had brought along as support lacked even a fraction of his or Li Ke's physical attributes and reflex metrics. Leaving them here meant they would be swarmed and systematically hollowed out by millions of toxic spiders before they could even unsheathe their blades.
They might stand a fighting chance against a massive, visible beast, but against a skittering carpet of venomous arachnids the size of mung beans, they would be completely helpless.
"I understand," Tengen muttered, his gaze boring into the dark silhouette of the mountain peaks ahead.
Kyojuro Rengoku and the rest of the deployed slayers were somewhere deep within that dark expanse, their current survival parameters unknown. But seeing this hyper-aggressive frontier outpost of mutated spiders, he could easily deduce the tactical nightmare waiting inside.
There was a very high mathematical probability that the native demons and those cosmic invaders had officially forged a unified front—coordinating their specific abilities to engineer a massive meat-grinder to systematically hollow out the Demon Slayer Corps!
"Order them to break away and fall back. The transit highway we utilized to arrive here should still be entirely safe," Li Ke noted, rolling his wrist.
He turned his head to mount up, only to find that his previous horse had long since panicked from the ambient spiritual pressure, bolted straight into the treeline, and had already been reduced to a heap of bleached white bones.
The executioners responsible for the high-speed stripping of the flesh were those exact same microscopic, mutated arachnids!
"Well, look at that..." Li Ke spat out a dry critique, turning his footing toward the mountain trail.
Although the remaining auxiliary slayers harbored a deep, bitter reluctance to abandon the field, they rigidly obeyed Tengen's absolute commands. Pivoting their mounts, they launched into a rapid retreat back toward the port city quarantine hub.
Tengen, however, didn't budge from the path. He firmly gripped the reins of his own mount alongside a secondary horse a departing slayer had left behind, gesturing a smooth invite toward Li Ke.
"I think it's far wiser if we launch our deployment into the thick of it together. After all, if I permit a strategic asset like you to navigate this anomaly entirely solo, Shinobu will probably hack me to pieces with her stinger blade when I get back, won't she?"
He delivered the dark, life-and-death gamble with a loud, characteristically booming laugh. In the grand cosmic scheme of things, his physical attributes merely outscaled the baseline metrics of common recruits; when pitted against these surreal, high-dimensional biological horrors, his absolute resistance parameters weren't significantly better than those of the troops he had just dismissed.
"Fair enough. My current energy reserves and elemental shields can reliably wrap around one or two teammates without breaking a sweat," Li Ke let out a soft smirk. He smoothly vaulted onto the saddle of the extra mount Tengen had secured, tracking his heading deeper into the corrupted mountain network.
The sun plunged beneath the western horizon at extreme velocity, aggressively drowning the surrounding topography in a suffocating, pitch-black gloom. The landscape warped into something intensely sinister, but Tengen's facial expression looked infinitely more severe than the dark woods around them.
Because the structural mutations overtaking the biome were getting completely unhinged!
Trees were contorted into grotesque, agonizing shapes that perfectly mimicked human beings screaming and thrashing in silent terror. Slithering through the upper canopy were anomalous, avian-winged serpents, while the undergrowth wriggled with amorphous, worm-like bio-forms that completely lacked defined mouths, digestive ports, or discernible skulls—a visual nightmare that screamed cosmic distortion.
High up in the timber, the native mountain monkeys stared down at their advance with blood-red, glowing pupils, their malicious glares locked onto the riders. The rhythmic chatter they exchanged sounded chillingly like hushed human whispers, aggressively grating against the Sound Hashira's nerves.
Worse yet, the solid, hard-packed forest trail that Tengen distinctly remembered from his past scouting maps had completely dissolved, mutating into a thick, viscous, and highly anomalous swampland. The swamp vented a foul, putrid stench heavily laced with a nauseating, sickly sweet pheromone aroma. Tengen was forcefully required to tear strips of cloth to completely blindfold and plug the nostrils of both their mounts, a mandatory logistical countermeasure to ensure the horses wouldn't collapse into blind panic from the surreal sights and smells.
Li Ke, however, was perceiving something far more profound through his unique vision.
"Just as I suspected... the baseline ecology here hasn't just been disrupted; it has been entirely rewritten."
He carefully tracked the systemic interactions of the mutated fauna. Bizarre, alien flora continuously secreted a glowing, viscous nectar, which was immediately consumed by low-tier organisms. These small creatures would then aggressively pack-hunt other native species before ultimately serving as the primary fuel source for even larger, more grotesque predators.
While the food chain looked intensely misshapen and unnatural, it functioned with an absolute, terrifyingly rigid harmony. From a purely objective biological standpoint, it was a perfectly self-sustaining cycle—meaning he and Tengen were now the only true foreign anomalies on this mountain.
Furthermore, whether it was the twisted wildlife, the predatory vegetation, or the thick swamp muck churning beneath their hooves, every single component of this environment radiated a heavy, structural malice. It felt as though the very atmosphere itself was actively trying to suffocate and reject their presence!
Worse yet, the local wildlife and swarms of floating insects continuously lunged out to ambush them. Li Ke was forced to constantly throw out loose arcs of fire to incinerate the attackers, aggressively torching the corrupted trees along the path to keep the ambient threat index manageable.
But the deeper they climbed into the structural center of the mountain, the more suffocating this rejection became.
Sensing that his lungs were working harder with every passing minute, Li Ke turned his head and questioned the Sound Hashira.
"Tell me—are you also picking up the sensation that the very air in this place is actively rejecting us?"
His breathing had undeniably grown heavy, a restriction his massive physical stats should have made impossible.
"I am... and here I thought my own exhaustion was playing tricks on my mind," Tengen replied, his teeth tightly gritted. "It's not just the respiration bottleneck. I can feel a savage wave of irrational, volatile irritability clawing at my chest..."
Tengen clutched his ribcage. For a master who had thoroughly perfected a physical Breathing Style, his cardiovascular awareness should have picked up on this chemical anomaly far quicker than Li Ke's.
A dark realization flashing through his mind, Tengen violently jammed his own fingers into his mouth, biting down with absolute, bone-crushing force. His facial expression instantly collapsed into a mask of pure horror.
The baseline level of physical pain he received was completely mathematically mismatched with the raw force of his bite!
"Dammit! It's a localized airborne neurotoxin! We've been heavily poisoned!"
The exact microsecond Tengen's warning left his lips, Li Ke slammed an open palm onto his shoulder, flooding the Sound Hashira and his mount with a sudden, massive discharge of Dragon Fire! Subjected to the intense, stinging heat of the healing factor, Tengen's horse violently reared and launched into a high-speed gallop, while Tengen felt the unnatural psychological rage and suffocating pressure instantly vaporize from his consciousness.
Pivoting smoothly, Li Ke blanketed his own mount in a secondary layer of Dragon Fire, forcing his horse to match the absolute, desperate velocity of Tengen's gallop as they chewed through the miles.
"This entire forest biome is a massive biological trap! We need to accelerate our pace, secure the Flame Hashira immediately, and then I am formally requesting you to burn this entire mountain to absolute ash, Li Ke!"
Tengen's face was dark with an intense fury. A systemic, high-density biological warfare anomaly of this scale had absolutely never been logged in the Corps' archives. But his primary tactical anxiety wasn't the environmental hazard—it was the survival index of Kyojuro Rengoku!
"Consider it done!"
Li Ke bellowed back his confirmation. Armed with the absolute defense of his dragon flames, he harbored zero fear toward elemental toxins or terrain debuffs.
By driving their mounts into an unyielding, high-speed sprint without a single care for stamina degradation, the duo rapidly closed the distance toward their designated rendezvous coordinates. But long before the structural layout of the base camp even came into view, Tengen's voice ground to a rigid, petrified halt.
At the exact coordinate where the Flame Hashira and the primary fortification of the Demon Slayer Corps were supposed to be standing, there was no outpost, and no sign of Rengoku.
There was only a massive, writhing sea of alien monstrosities.
These monsters were a translucent, sickly green. Their outer epidermis was completely clear, exposing a dense interior flooded with thick chartreuse slime and semi-transparent, pulsing organs.
They possessed no conventional legs, forcing their entire weight to move via a rhythmic, peristaltic writhing of their lower torsos. Their skulls had been completely erased; in their place rose two grotesque, columnar stalks supporting oversized, bulging eyeballs.
Though stripped of lower limbs, they possessed bloated, pupa-like arms terminating in stubby digits, paired with a horrifying, circular, ring-shaped maw packed with concentric rows of needle-sharp teeth.
Their entire structures radiated an eerie, luminescent green glow as they continuously scanned the perimeter. Yet, what struck Tengen Uzui into a petrified, suffocating silence wasn't the grotesque anatomy of these anomalies—no veteran of the Corps would ever falter from mere ugliness.
It was because these monsters were still wearing the standard black uniforms of the Demon Slayer Corps.
"YOU BASTARDS!!!"
Tengen completely lost his sanity. He could rationally accept his fellow slayers being slaughtered by demons or torn to pieces by alien horrors; that was the fundamental, blood-soaked destiny they all walked when they picked up a blade. It was the honorable price of a life-or-death struggle.
But he absolutely, unconditionally could not tolerate them being mutilated into mindless cosmic cattle!
It was a direct, violent desecration of their entire unyielding willpower!
He refused to permit it!
"Calm down, Tengen! Stand down! There might still be a way to salvage them!"
Li Ke instantly threw his immense physical weight into pinning the Sound Hashira before he could launch into a suicidal charge. Through the radar of his Observation Haki, he had just picked up a highly anomalous detail: these transformed scouts harbored absolutely zero malice.
The structural reality of the battlefield backed up his assessment. The exact microsecond he and Tengen ground their mounts to a halt, the luminescent green creatures let out frantic, high-pitched vocalizations. They began rhythmically swaying their bodies, executing a series of desperate gestures and emitting a chorus of distorted, garbled noises. The sheer, abstract distortion of their movements was enough to make Li Ke's stomach violently turn, but he forced himself to hold his line.
Sensing that their vocal cords were fundamentally incapable of executing human speech to communicate, several of the uniform-clad monsters abruptly knelt down. They began frantically scraping their pupa-like fingers into the dirt to carve out written characters. Once the message was completed, they gave a weak, lingering wave of their hands toward the duo, turned their writhing forms around, and systematically evacuated the ruined camp.
Only after the entire translucent horde had fully receded into the deeper slopes did Li Ke and Tengen cautiously advance into the center of the clearing to analyze the carved text.
"Do not approach us. Direct contact with our bioluminescent light or the slime within our flesh will trigger an instantaneous transformation. Continuous exposure to the green light for over one hour will also warp your baseline human anatomy. We are currently bound by the absolute commands of the Black Mother; there is no path back to what we were. Our sensory wiring has mutated... Humans smell... delicious... The native demons have forged a unified front with them... We overheard mentions regarding Muzan Kibutsuji... though we cannot verify if he is physically present on this mountain. The Flame Hashira successfully resisted the conversion; he has marched deeper to avenge our humanity, find him immediately! We... we are physically blocked from exposing the coordinates of the Black Mother! Our cognitive willpower is slipping... All hail the Black Mother!"
The jagged, trembling stroke lines of the text mapped out the literal, chronological decay of their human consciousness. What broke Tengen's spirit entirely was the final line; it was blindingly obvious that by the time the writer finished the warning, their core soul had been completely rewritten into a mindless, fanatical thrall of this alien entity.
Tengen's chest thrummed with a white-hot, systemic rage.
And beside him, Li Ke's expression settled into a mask of pure, absolute fury.