Heart Devil [OP Yandere Schizo Ramble LitRPG XD]

The Dream Faction moved without hesitation. Fueled by command, determination, and subtle desperation.

At the center of this storm of stolen authority was Lazmer the 22nd Acedia, Advisor and strategist of the Dream Faction, and a man who smiled too easily for someone burning his own future.

He watched from the rear command post, nestled within an illusionary fog that only his men could pierce. The cliffs of Hazy Mountain loomed ahead, but to Lazmer they already belonged to him in spirit.

'Too long have we been patient.'

'Too long have we let that fool Baku rot atop what should have been ours.'

Lazmer's fingers twitched across the scroll array in front of him, channels of inked runes feeding into the siege weapons poised at his flank. The Scatterthoughts, heavy iron ballista bolts wrapped in hallucination scripture and dazing glyphs, were ready to fire.

"Begin."

With the flick of a command talisman, the first barrage launched.

The bolts howled through the fog like dying birds. Upon impact, they didn't explode with fire or shrapnel, but with a psychic static, a hazy ripple of magic that bled confusion into the air itself.

Where they struck, the lower terraces of Hazy Mountain twisted subtly in color and shape. The Dream Knights stationed there faltered, their formations slackened, their thoughts clouded. Commands were heard but not understood. Responses were given but not trusted.

This was the purpose of Scatterthoughts, A slow bleed of purpose from mind to mist.

Above, the three enforcers, all 5-star ranked, moved swiftly under cover of the confusion.

Their armor bore the pale sigils of the Dream Faction's high enforcer corps, shimmering with defenses against illusion and nightmare alike.

Their orders were simple in design, if not in execution:

Seal Baku within a dreamscape, for good if possible.

Kill the young devil Hannya to destabilize her growing faction and in turn, the dreamveil compact.

Secure the dream cores for the Acedia family, for market rebalancing… amongst other variables known only to the commander of this operation.

They whispered amongst themselves as they ascended, gliding between rock faces on conjured winds.

"The scouts reported no resistance past the second terrace. His Dream Knights are compromised."

"It's true, then. His power waned decades ago. He's no longer fit to guard this place."

"The Acedia will reclaim what's ours. Greed took too much from us before. We won't let this slip away as well."

"Once the upstart falls, her alliances will unravel. The Capital Council will have no choice but to recognize the transfer."

Their words grew lighter as they climbed. Less caution, more certainty.

But then…

The color began to drain from the world.

Slowly at first. A leaf here, a stone there, becoming washed of hue until everything settled into a palette of dull greys and pale silvers.

The wind stopped feeling like wind.

The air thickened with a weight that couldn't be formally called pressure.

Their magic talismans flickered uncertainly. Their mana barriers tingled at the edges.

"What is this…?" one whispered.

"Dream magic…"

They had studied Baku's past techniques. They knew his record, a 4-star devil, skilled in dreamcraft but never considered a threat outside his assigned position, this mountain. His strength had been in patience, in petty schemes and eating dreams.

A bane to most of the devils of Acedia.

But never raw power, not really, not to them, 4-star devils had a potential limit.

Or so they thought.

He appeared without a single ripple of energy. Not even a gust of wind.

Simply… there.

Laughing.

"Kahuhuhu!"

The sound grated against the enforced calm of their minds like steel on flimsy silk.

He stood between them and the path forward, silver samurai armor dulled with age but flawless in polish, his powder blue Dream Knight robes trailing mist like a breath in winter. His bald head glistened with domineering battle wisdom, his face lined but firm as he grinned down at the group.

Baku's eyes gleamed through the monochrome world.

Empty… and furious.

"You children really thought you understood how this mountain breathes?" he asked, voice like broken bells and grin wide like a famish wolf. "Three five-stars. A pitiful number. Not enough. Kahuhuhu! Not even close."

The lead enforcer stepped forward, summoning his weapon.

"Baku of Hazy Mountain. By authority of the Acedia and the Dream Faction-"

"Authority?" Baku laughed again. Shorter. Sharper. "You speak of authority on my mountain? In my house?"

The monochrome sky cracked faintly overhead.

"No. You won't be giving orders here."

He stepped forward once. The earth seemed to crumble away behind him, like reality stopped where he no longer stood.

"You've come into my dream. And you won't be waking up."

Caldeon, known within the Dream Faction as 'Precision Incarnate', didn't flinch, he thought this move of Lazmer's was rash, but he didn't disagree with his assessments, so he followed orders.

He stepped forward with a calm that seemed carved into his bones, ignoring Baku's theatrical show of domain authority. Where others felt the oppressive weight of the monochrome world settling onto their shoulders, Caldeon remained perfectly upright.

Baku's strength didn't concern him. Not here.

"Dream Eater… They say your time has passed. I'll prove them right."

On either side of him, his chosen enforcers took their positions.

Ryoha to his left, in pale armor laced with violet-blue runes, her twin sabers already humming with anticipation. A specialist in cutting through false spaces and illusions.

Jeron to his right, cloaked in dark spell-thread, his halberd fixed like a spear against reality itself. His defenses were among the strongest of any 5-star devil in their faction.

"Proceed." Caldeon's order was clear, simple, without wasted breath.

Baku's grin remained unchanged. "I hope you children truly came prepared."

Caldeon ignored the bait. His hand moved in a practiced motion, grabbing the hilt of his blade.

"Tenet: Endless Slumber."

His words invoked the change, reality folded inward. The grayscale surroundings twisted, space warped, and a pocket dimension bloomed within Baku's monochrome world.

Baku's brow lifted slightly.

"...Paradoxical, is it?"

Endless Slumber wasn't meant to overwrite Baku's domain. Instead, it created a separate sealed world within any existing space. Like placing a cage inside a garden. Once triggered, it ensnared the targets in a realm where Caldeon's rules were absolute.

Baku had expected a tool, an artifact, perhaps even a coordinated sigil strike. What emerged caught him off guard.

From the bleeding cracks of space, something inhuman slipped free. A creature without hands, stitched shut at its eyes and mouth, trailing threads as its body unraveled and rewove itself in endless patterns.

Without hesitation, it coiled around them all, dragging them into the fractured heart of the new dreamscape.

"Good night, Dream Eater," Caldeon said.

The four figures vanished, swallowed whole.

Outside, Sweet Dreams remained active across Hazy Mountain. The sky hung frozen in lifeless grey, and Baku's own mythical monster lingered, sleeping high above in the cloudline, untouched by what had transpired, and unable to invoke Baku's own rules.

Inside this prison, none of that power reached.

Baku landed on solid ground, boots landing across something like cracked glass stretched over an abyss. Above them hung a sky with black chains and sleepless, bloodshot eyes.

Ryoha moved without hesitation to cover Caldeon's flank. Jeron readied his defenses, halberd rotating once in his grip, planting sigils beneath his feet.

"This isn't a battle of attrition," Ryoha said flatly. "End him quickly."

A case of theft: this story is not rightfully on Amazon; if you spot it, report the violation.

"Agreed," Jeron nodded. "Baku's unpredictability is the true threat. Give him no time to think."

Caldeon nodded in silent agreement. This was his realm now. The Endless Slumber's influence would corrode Baku's stamina, fray his mind, and warp his perception of time itself. Hours could pass here in moments outside. His mythical monster's presence would suppress regeneration and bleed away defenses slowly but surely.

"I'll admit," Baku said, his tone shifting as he rolled his shoulders beneath his armor. "Not bad."

He exhaled.

A soft hiss escaped his mouth, spilling into the stagnant air as sparkling grey fog began to seep from between his teeth. The mist carried a subtle glimmer, like starlight crushed into dust.

"But you've made a small mistake."

"Oh? Do tell."

"You assumed I needed my tenet to win."

Baku's hand fell to the sword at his side. The polished black sheath bore no ornamentation, only the faded crest of a forgotten dream clan etched faintly near the guard.

"You've never fought someone who spent thousands of years mastering combat within lucid dreams."

Baku's mind emptied.

"Allow me to demonstrate."

CLICK

Steel hissed free. The blade shimmered, thin and perfect, humming quietly with restrained force.

Caldeon's instincts screamed the moment Baku's blade moved.

The speed was jarring, but it was more than that.

It was something purer, something older.

The sword split the stagnant air with a simple draw. Only a silver streak so fast it left the eye struggling to track its edge. The very atmosphere seemed forced to correct itself after the cut had already been made.

Jeron barely brought his halberd up in time. Sparks showered from the contact as his defensive sigils groaned. He gritted his teeth, already feeling the strain pressing into his arms.

"That… that wasn't law-based."

Ryoha moved next, fast and sure, her twin sabers crossing to form a defense. Baku's second step vanished in the dull shimmer of mist beneath his feet. He reappeared at her side, the blade flashing in a short arc that forced her to twist away, her armor scoring lines of smoke where his sword kissed it.

Her breath caught. His movement had been clean, natural, almost lazy. Yet somehow it bypassed her guard like water seeping through cracks.

"It's not sorcery… He's using a technique. A martial style."

"Don't let him control the pace!" Caldeon ordered.

His own blade snapped free from its sheath, blue runes crawling up its length as he struck out to intercept Baku's next approach. His precision was as sharp as his title demanded. Angles calculated. Distance measured. Every step accounted for.

And still Baku's sword found him first.

It wasn't the speed, It was the timing. Perfect, merciless timing honed over thousands of years.

The flat of Baku's blade struck Caldeon's wrist, redirecting the sword with humiliating ease before the tip snapped upward, grazing across his chest plate with a hollow clink. A warning cut, not a finishing one.

"Your thoughts are too loud." Baku said. His tone sounded like it was simply a statement of fact.

Caldeon's eye twitched. Ryoha and Jeron fell in behind him immediately, adjusting formations.

"Shift to pattern red."

Sigils flared beneath their feet. The artificial sky groaned as layers of suppression magic rippled outward. Chains from above descended to anchor them further. The monster tied to Eternal Slumber stirred, extending threads of nightmareweave to reinforce their footing.

"You cannot cut what isn't part of reality," Jeron growled. "This place obeys us."

A snort followed.

"That's what you believe." Baku replied.

The mist thickened, sparkling grey billowing from his mouth. His sword dipped, then rose, tracing a crescent in the air.

The ground buckled, feeling the sheer intent. His stance shifted again, feet sliding with precision only dream combat could refine. His blade vanished into a draw so fast it seemed not to exist, only for the afterimage to cleave the chains descending toward him into harmless fragments.

The world around them protested. The rules started to fray.

"Impossible!" Ryoha's eyes widened. "He's severing the bindings through… through just some technique?"

Caldeon clenched his jaw. "No, It's not the sword. It's… something else."

He could sense it within his pocket dimension, reality was being adjusted, With each strike laws were bending. The rules were not breaking, more like making exceptions.

Baku took a step forward. None of them could see it.

Behind Jeron's defenses, his halberd swung in desperation, only to meet the sheath's edge in a perfect parry.

A subtle flick of Baku's wrist sent Jeron sprawling, armor cracking beneath the redirected force.

"Not bad for a 5-star, but you're wasting my time."

Ryoha lunged with both sabers flashing. Baku met her head-on, his blade moving with a calm, almost detached rhythm. Every strike she offered unraveled on his edge, every clash dismantled her footing further.

Her breath shortened. Her form broke down.

"How is he doing this? His style… it's not recorded. No ancestral knowledge, not in any archives."

"Of course not," Baku answered without looking at her. "Because the style isn't from the Acedia, nor this plane."

He shifted again, stepping past her guard, the pommel of his sword knocking against her helm with surgical precision. She dropped, to her, the impact was felt before she hit the glassy ground.

Caldeon moved, abandoning formation. His sword screamed with blue light now, runes burning brighter.

"Enough tricks."

"Agreed."

Their blades met. Once. Twice. A third time. Each clash peeled apart the fabric of the dreamscape, revealing glimpses of Baku's monochrome world bleeding back in through the cracks.

Caldeon realized it too late.

Baku wasn't fighting to defeat them.

He was cutting his way out.

~~~

Lazmer stood at the upper ridge of Hazy Mountain's midpoint, watching the dreamscape fracture from the outside in. His face was locked in a grim mask.

The cracks shouldn't have been forming. Not this fast. Not against a paradoxical tenet.

"Tch… not even ten minutes."

He adjusted his gloves with slow irritation. The surface layer of Endless Slumber peeled back like fragile skin beneath a knife. Baku wasn't overpowering it with laws, that was calculated. He wasn't countering it with a paradox of his own, that was calculated. Yet still, here he was, carving through with nothing but sheer will and honed skill.

That was far more troublesome.

He gritted his teeth. "Baku… you ancient bastard."

He turned from the sight with a snap of his coat. His gaze fell on Dozeuff, who sat perched on a jutting rock like a disinterested observer, one leg lazily swinging. His crest of house pride gleamed silver beneath his collar. Soon, he would be stepping into the role of a young council member of the Dream Faction.

If… when this mission succeeds.

"Find that young devil Hannya. Now."

Dozeuff's eyes lifted. "She's still hiding?"

"Somewhere. Likely deeper in the sanctum. Isolated, waiting for this to pass. Kill her now before things try to take another unexpected turn."

Dozeuff gave a slow, theatrical yawn. "Fine. I needed to stretch anyway."

He vanished into the thinning mist, steps light as silence, Lazmer didn't bother watching him leave.

Instead, his attention turned to the four shadow demons waiting near the prepared equipment. Each bore the sigils of shadow manipulation across their skin, their bodies designed for infiltration and manipulation of soft-spaces.

"Prepare the tether. We'll use the fissure."

Obediently, one demon lifted the sealed case and opened it, revealing a hook of obsidian etched with runes, glyphs specialized to bind unstable dream constructs. From it, trailed a tether, runed links glowing faintly in the color of ash.

One end already anchored to Caldeon's collapsing prison. The other would be sunk directly into the fissure.

Lazmer's eyes flicked upward.

Above the plateau, just a few hundred feet beyond the current battlefront, the sky itself was torn. A gaping rupture hovered mere feet above the flat plane. From it, dream mist bled down like breath from a sleeping giant's mouth.

That mist didn't obey natural laws. It slowly eroded reality wherever it lingered for extended periods. Shapes bent where it touched them, thoughts twisted, and living creatures exposed for too long contracted lulling virus, a degenerative curse that eventually transformed flesh into nightmare, birthing beasts tied to the dream world itself.

"Anchor it directly to the fissure. Siphon the raw mist into the dreamscape."

"The contamination?" one demon rasped.

"It will reinforce the barrier, or ruin it, either way, it solves my problem."

They obeyed without further question. As they moved, Lazmer watched the tether uncoil like a living serpent, latching to the mist above. The hook embedded into the fissure's edge, anchoring their artificial domain to a deeper, wilder source of dream mist.

The results were immediate.

The mist thickened, began to creep faster, curling like fingers around the edges of Caldeon's prison. The cracks stopped spreading, arrested by new fuel, but the sky took on sickly hues. Splashes of pale violet, fading blues, and inked black rippled outward as the corruption spread.

The shadow demons worked silently, maintaining distance from the mist even as it responded to their glyphwork.

Lazmer exhaled through his teeth. "Stall him, Caldeon. Just a little longer."

Even he wasn't certain how stable this would be. The fissure's mist wasn't something mortals were meant to interact with directly. It wasn't magic, it wasn't anything structured enough to be controlled easily. It was raw dream… and contamination was inevitable.

But so long as it held Baku…

His gaze lifted again toward the cracks barely concealed above. His grip tightened faintly as the tether pulsed once, as though in answer to his urgent thoughts.

~~~

Baku felt the change before he saw it.

The edges of the dreamscape were no longer stable. What had begun as neat fractures now ran wild like veins of rot, and from those wounds, a creeping fog oozed inward. Not the structured laws of Endless Slumber's construction. This was raw, untamed dream mist, bleeding directly from the fissure now tethered to this realm.

Far from the docile mist he let flow throughout the mountain range.

It curled along the boundaries, bringing with it the stench of distortion. Baku could see the first signs of contamination already at play.

Dream fissure Haze, poured directly from the source.

Where the mist thickened, it spawned shapes. Misshapen beasts, half-formed nightmares clawing themselves into existence. Rabid creatures with too many limbs, mouths where eyes should be, crawling on skeletal joints toward whatever heartbeat they sensed first.

"Ahh… so that's your answer, huh?"

Baku's grin widened despite himself. His laugh broke free, harsh and barking.

"Kahuhuhu! Good! GOOD! Bring them all in, throw your scraps at me! Let's see how long you last trying to hold me here!"

The fog thickened, and so too did the pressure of his opponents' resolve.

Caldeon's blade blazed brighter now, runes shifting as he pushed his Eternal Slumber deeper, reinforcing the structure with all the authority his Tenet could muster. But even he knew, it wouldn't hold forever.

"Stop him now," Caldeon ordered through clenched teeth. "Or this will all be meaningless."

Ryoha and Jeron didn't hesitate. Together, they triggered their Tenets, not paradoxical monstrosities, but potent enough to overlay personal laws across a field of battle.

Ryoha's sabers scattered mirror-like fragments through the air, locking space into repeating loops with each cut. Movements within her range repeated unnaturally, dragging Baku into mirrored traps again and again.

Jeron's halberd emitted sigils that solidified into armored phantoms, guardians to reinforce his defenses, drawing spears of condensed law to strike down anything unnatural.

The beasts born from the creeping haze rushed first. Ryoha cut them down with methodical precision, but more always followed. Jeron crushed what reached him beneath sheer force and binding arrays.

Through it all, Baku moved undeterred.

His sword hummed against reality, parting the creatures as if slicing threads loose from a tapestry. His steps faded through Ryoha's loops, breaking her patterns by stepping where no step should be. He laughed as Jeron's constructs shattered under the weight of experience older than their bloodlines.

"You children play with laws. But to me, they're irrelevant."

Still, he could feel it, the weight of time stretching thin. The fissure's mist would buy his enemies more moments, and he couldn't tear free fast enough without opening himself to unnecessary damage.

'Tch… Noh… I hope you're handling the fools outside properly.'

He stepped through another strike, cutting a path through the growing horde.

~~~

Elsewhere on the mountain…

Dozeuff's stride was a leisure mockery of effort. Where Dream Knights appeared, he cut them down with lazy flicks of his black-bladed scythe, the edge carving corpses with casual disdain.

Their screams barely registered. They were ants in his path, nothing more. His focus was ahead the sealed sanctum nestled deeper within the mountain's heart.

It didn't take a genius to sense it now.

The pressure bleeding from behind that barrier was unlike anything a low-star devil should emit. It radiated not outward, but downward, curling in on itself like something about to hatch.

Dozeuff's lips twisted into a grin far too wide.

"Heh… found you."

Standing before the entrance was a lone figure.

Shela. Half-demon. Half-devil. An imp masquerading as a soldier, her lineage as much a stain as her blood. Her posture was steady, her hand resting at her side, the air around her cold enough to mist.

Dozeuff slowed to a halt, observing. Measuring.

He hadn't expected a guard, nor had he expected that same chill in the air. His senses told him there was something strange about this one, a creeping influence, a law of frost layered too deep to unravel easily. Absolute Zero, though he did not know the name.

"Cute. They left a mutt at the door."

Shela said nothing. Her gaze locked onto him, steady and unwavering despite the hunger in his expression.

He took a step forward, raising a hand lazily toward the sky. The air began to shiver, reacting to the stirrings of his Tenet. A law field thick with narcotic rain, soon to be unleashed. A realm where laws bent to Mercy Is Wasted on Sleep, where spells collapsed and illusions drowned beneath fogged perception.

"I don't have time to waste, little imp. Step aside, and maybe I'll show you mercy when I'm done inside."

His eyes flicked to the cave mouth, feeling the swelling potential beyond it. Hannya was evolving.

What a delightfully vulnerable moment that would be.

He could already imagine how best to… educate her in submission. His grin sharpened at the thought.

Shela took a step forward in kind.

"If you think I'm moving aside… you're dumber than you look."

Cold blossomed underfoot, creeping cracks of ice splitting the ground in perfect silence. Her aura burned chill against his fog, unmoved by his presence.

Dozeuff's grin didn't waver.

"Then I'll break you first."