Fate's Slave - Shadow Slave X Honkai Star Rail

Sunny did not know whether he was still screaming.

The sensation of having nerves was gone. There was only heat — white, devouring, intimate — like a star had been threaded through his spine and left there to smolder. His body convulsed in the frozen courtyard, but inside, the world had already been stripped down to something far more fragile.

Phantylia moved through him like a sovereign inspecting conquered territory.

Her presence was not merely invasive. It was proprietary.

The green radiance that had once hovered above Tingyun’s corpse now suffused the caverns of his mind, peeling back defenses not by force, but by insight. Locks clicked open because she understood their mechanisms. Walls dissolved because she recognized the fear they were built to contain.

"Oh?"

Her voice was layered, echoing from thousands of unseen throats.

"How quaint."

Narcolepsy.

Not as a medical condition — she did not see it in such limited terms — but as a metaphysical scar. A rhythm broken before it had ever properly formed.

She traced it delicately, like a scholar brushing dust from an artifact.

"How fascinating. The root of a Self-Annihilator... though not born from the self."

The phrase carried weight. In her understanding, Self-Annihilators were those whose minds turned inward and devoured themselves — paradoxes of Nihility who were both consumed and not consumed by IX.

Sunny’s mind did not collapse.

It fragmented.

Sleep intruded upon wakefulness. Dreams intruded upon reality. Consciousness flickered and stuttered like a faulty lantern. A defensive mechanism, yes — but not one he had crafted.

She pressed closer, examining the way his brain chemistry had tangled with his soul.

"Not self-inflicted. A flaw in the pattern. A misaligned stitch in the loom of Fate."

She could remove it.

With a thought, she could smooth the errant currents, seal the leaks between dream and waking. She could grant him uninterrupted consciousness.

But she hesitated.

"...No."

Her laughter softened into contemplation.

"The damage is permanent. The interruptions, the forced descents into unconsciousness — they have carved channels through your psyche. Remove the cause now, and the mind will collapse under the weight of its own unfiltered chaos. Hallucinations. Dissociation. Perhaps even a clean fracture into true annihilation."

She drifted away from that region of his mind with faint distaste.

"You are unstable enough as it is. I require you functional."

Sunny, suspended in the mire of his own mental landscape, clutched at his head.

He could feel her fingers — not physically, but conceptually — sliding between memories, tugging at synapses, testing which strands would unravel first.

"Now then..."

Phantylia whispered, bright with anticipation.

"Let us begin at the beginning."

Darkness.

Then sensation.

A child’s first coherent awareness — not infancy, but the moment consciousness crystallized enough to form narrative. A cramped apartment in the Outskirts of the City of Preservation.

Phantylia observed.

"A child born from two almost-normal humans. If it weren’t for the fact that the father possessed pseudo-prophetic intuition... and the mother carried the innate ability to tie the world to a name."

She examined them in turn.

The father: large for his demographic, wielding a humorous cockiness that hid his exhaustion and fear. But beneath that? A tremor in probability. A subtle leaning toward correct decisions. Not true foresight — merely intuition sharpened beyond human norm. Enough to survive risks others would not.

The mother: observant and chipper, holding a mind that could find optimism in hell itself. Words that lingered. Names she spoke that seemed to settle into reality more firmly than they should. She did not know what she was doing. But when she called her son stubborn, the world adjusted to make it so.

Phantylia hummed.

"Completely unaware.

She turned her attention to the children.

"A problematic, anti-social, borderline-sociopathic son... and a daughter with the soul of an Angel — metaphorically, of course."

Sunny writhed. Phantylia continued with a light tone.

"Ah... So this is the City of Preservation."

Towering walls. Corporate sigils. The distant authority of the Interastral Peace Corporation casting its long shadow over everything.

"How humorous... that the IPC’s grand experiment both succeeded and failed in the worst and best ways possible."

The memory shifted.

The father laughing softly at dinner.

Then absence.

"Supposedly died in a construction accident. In reality, he had been supplementing his income with mercenary work. Intuition guiding his hand, ensuring survival — until it did not."

Sunny screamed as images flooded his head.

The scene replayed from angles he had never seen. His father’s last job. A calculation misjudged by a fraction. A bullet where instinct faltered.

The green light pulsed with delight.

"In a place where a decent job meant barely affording a single room... he gambled with his life. And lost."

The mother’s decline followed.

Factory shifts stretching longer. Coughing into fabric that grew darker each week. Hands trembling as she stitched labels onto products destined for wealthier districts.

"The arrogant son cared for his little sister, ignorant of the Fate that befell the woman who sired him."

Sunny dropped to his knees in the mental sludge.

On her deathbed, his mother’s lips moved.

Her last wish.

A wish spoken softly, without understanding its weight.

A wish that tied itself to him like a chain.

Phantylia’s laughter sharpened.

"A wish only a Masked Fool would give for their own amusement."

It had not been a command to the world.

It had been a declaration.

But her talent had nudged reality regardless.

Phantylia cooed, circling him in the mire.

"And you see, curses are very much real. That blacksmith among your fellow terrorists? He manifests them deliberately. Engraves them upon steel."

Fate twisted.

"Yet what is steel compared to a mother’s dying words?"

The mud rose higher, seeping into Sunny’s skin.

"There is no curse more cruel than love."

The agony intensified.

Sunny clawed at his throat, trying to breathe in a world without air.

***

Phantylia’s laughter rolled through the mire like oil catching flame.

"Orphaned, the boy used the last of the money left behind by his mother to secure a spot in a well-off orphanage, for both himself and his sister. Such foresight. Such devotion. Both children were oh so adorable. Cleaned and fed, their large eyes and careful manners made them irresistible prospects. Many families considered adopting them. They saw a sweet little girl with bright smiles and a quiet, intense older brother who seemed fiercely protective."

The mud around Sunny thickened, rising to his chest as scenes replayed in merciless clarity. He saw himself standing too close when adults spoke to Rain. He saw the way his answers came too quickly, too sharply, how he measured every expression, every tone, dissecting hidden meanings that did not exist. He saw the flash of something ugly in his own gaze when a prospective mother ruffled his sister’s hair.

Phantylia’s voice grew lilting with amusement.

"Until the boy’s selfish, deceitful, and vile personality came out on full display. Possessiveness disguised as love. Manipulation disguised as concern. Distrust dripping from every word. He did not want a family for both of them. He wanted ownership. And humans, fragile creatures that they are, recoil when they glimpse a predator in a child’s skin."

One by one, the offers disappeared. Smiles turned strained. Applications were withdrawn. The sister remained charming. The brother became an inconvenience.

Phantylia went on, circling him like a carrion bird.

"Eventually, a family grieving for their eldest son who died in his First Nightmare came searching for something to fill the hole in their home. Replacement is such a human instinct. They wanted light. Gentleness. A balm for grief. The sweet and sociable little girl was perfect. The brother was unnecessary baggage that would only taint her."

Sunny felt it again — the day Rain left. Her small hand slipping from his. Her confusion. Her reluctant hope. The way he had smiled and told her it was fine.

"And so, she was adopted, and he was left alone. The start of a vicious cycle."

Tears streamed down Sunny’s face.

"Stop... stop...!"

The green radiance flared brighter.

"Twisted and self-centered as he was, the boy convinced himself that his sister would not be happy. That she would miss him desperately. That wealth and safety meant nothing compared to his presence. Seeing himself as her hero, he left the orphanage, scrounging up money through whatever means necessary."

The memories sharpened into something unbearable. Narrow alleys. Cheap motels. The metallic scent of blood. The rehearsed smiles he offered to lure targets close before slipping a blade between ribs. Theft and murder woven seamlessly into survival.

"Both crimes often covered by the false offer of prostitution. A clever strategy. After all, besides his own sister, the boy saw others as nothing more than animals. Creatures to be slaughtered and eaten, or allowed to roam free in his garden at his leisure."

At some point, Sunny stopped crying. The anguish drained away, replaced by something colder. He lifted his head and stared at the hovering orb with naked hatred.

Phantylia noticed the shift. She did not pause.

"Eventually, after years of sin piled neatly upon his back, the boy accumulated enough to hire a private detective. Information is expensive, even in the slums. He located his darling sister. Unfortunately, she resided in the only place an Outskirts rat such as himself could not enter."

Images surfaced of guarded gates and polished streets. Of security patrols and surveillance lenses. Of barriers both physical and social.

"And yet, ever resourceful, he managed to sneak in anyway."

The memory struck like a blade. Sunny crouched in the shadows of manicured hedges, peering through a lit window into a home that glowed with warmth. He saw Rain seated at a dining table, laughing. Well-fed. Dressed in clean clothes. A younger child tugged at her sleeve. Another sibling leaned against her shoulder.

Phantylia whispered, her tone almost gentle now:

"Face to face with his foolish dream, separated by a mere window, he understood something. His arrogance cracked, though it did not shatter. He was not needed."

Sunny’s chest tightened.

"She was well-fed. Smiling. Surrounded by affection. She had younger siblings of her own. She had parents who watched her with pride. There was nothing to rescue her from."

Envy, anger, despair, doubt — each emotion replayed in merciless succession. He remembered wanting to break the window. To drag her out. To demand gratitude. He remembered imagining what would happen if that house burned.

Phantylia continued, her voice ringing theatrically across the sludge-filled landscape.

"But despite his twisted nature, he turned away. He left without revealing himself, returning to shadows he was born from. The first and last selfless act of his life."

The words struck deeper than any accusation.

"And so, the Seed of Corruption was planted."

The mire trembled.

"And yet, despite having no meaning to live, despite no longer believing in his mother’s dying wish, he refused to surrender. Each step he took was no longer driven by love but by hatred. Hatred for the world. Hatred for those who lived within it. Hatred for his own arrogance and weakness. And with nothing but spite and a grudge in his heart, he prevailed."

Her laughter rang sharp and bright, filled with genuine admiration and cutting mockery in equal measure.

Then something shifted.

Sunny felt it first — a thread snapping somewhere deep within. A pressure building behind his eyes as fragments surfaced unbidden. Memories that had been there, then not there, then there again.

An unaging man standing before him in impossible calm, telling him to give up. Sunny could not recall the man’s face. He only remembered the absurd urge to both fist bump him and punch him.

A green-haired coward with a talking tail. He could not remember her name. Only the strange desire to tease her mercilessly.

A girl with sunset-colored eyes he pulled through a field of fireflies. He could not remember her voice. Only the simultaneous urge to kiss her and flee from her warmth.

A grey-haired girl with an empty gaze. He could not remember their conversations. Only the instinct to place everything he owned into her hands.

He wanted so much.

But he could not remember why.

Phantylia’s narration faltered. The green light flickered as she probed deeper, trying to seize those fragments and unfold them properly.

The mud beneath them began to drain away.

It did not evaporate. It receded, pulled outward as though swallowed by an unseen tide. The suffocating sludge transformed into water — clear, endless, reflecting the sky above.

The darkness parted to reveal a vast ocean stretching toward a glowing horizon. A sandy shoreline formed beneath their feet, warm and solid. The sun hovered low, staining the sea gold and crimson as it prepared to sink.

Phantylia stilled.

"This... is not of my making." 𝐟𝕣𝕖𝐞𝐰𝕖𝚋𝐧𝗼𝚟𝐞𝕝.𝗰𝐨𝐦

She attempted to twist the scene back into something she controlled. The ocean did not respond. She tried to rise higher, to retreat beyond the bounds of the mental construct she had shaped.

She could not move beyond the shoreline.

For the first time since entering Sunny’s mind, a faint thread of unease wound through her voice.

"Where am I?"

The waves rolled in gently, lapping at the sand with rhythmic certainty. The air carried the scent of salt and something impossibly clean. It did not burn with Destruction. It did not rot with corruption. It simply existed.

Far ahead, near the water’s edge, a solitary figure stood facing the horizon. The silhouette was unmistakable — slender, still, hands resting loosely at his sides.

Sunny.

Not writhing.

Not screaming.

Not drowning.

Standing, staring into the distance with a confused expression on his face.

Phantylia drifted forward, cautious now, her green glow muted slightly by the ambient light of the setting sun. The sand did not sink beneath her presence. The sea did not recoil. This realm acknowledged her but did not bend.

"You are being very inconvenient."

Her voice lacked its usual certainty.

The figure at the shoreline did not turn.

The sun dipped lower, half-submerged in the ocean, scattering molten light across the waves.

Phantylia felt something unfamiliar press against her consciousness. It was not resistance in the violent sense. It was not hatred, nor denial, nor fractured instability.

It was depth.

An expanse vast enough that her probing felt shallow by comparison. Not chaos — but layered stillness. Not annihilation — but containment.

The sea stretched endlessly, patient and unmoving beneath its surface currents.

For the first time, Phantylia understood that she was not navigating a broken mind.

She was standing at the edge of an ocean she did not yet comprehend.

***

Phantylia did not rush.

For the first time since she had invaded Sunny’s mind, she did not prod, did not peel, did not narrate. She simply floated along the shoreline, her green radiance dimmed beneath the gold wash of the setting sun. The sand was warm beneath her presence, though she did not touch it. The waves advanced and retreated with gentle persistence, their rhythm indifferent to her scrutiny.

Sunny stood at the water’s edge, staring at the horizon as if something vast and private was unfolding there — something she could not see. His expression was not pained. Not fractured. It was... contemplative.

Then, without warning, he tipped backward.

He fell into the sea with a soft splash, limbs loose, body surrendering to buoyancy. He floated on his back, eyes half-lidded, staring up at a sky painted in amber and rose.

"My sunset..."

He muttered faintly, as if claiming ownership over the dying light.

Phantylia narrowed her glow.

This was not how a conquered mind behaved.

She turned away from him, unwilling to dignify the absurdity with further attention. The shoreline stretched endlessly in both directions. The ocean mirrored the sky so perfectly that horizon and water became indistinguishable, as though the world had been folded in half.

She moved.

Time here did not behave. She drifted forward for what felt like minutes, then hours, then perhaps only a heartbeat. The sun did not sink further. The tide did not change.

And then she saw them.

Three figures splashing in the shallows, no more than twenty paces from where the water deepened. Teenagers, by appearance. Laughing. Shouting. Entirely unconcerned with the presence of an Emanator of Destruction drifting toward them.

The first girl had snow-white hair tied high in a ponytail, bright blue eyes flashing with mischief. She clutched something slippery in her hands — a wriggling sea slug — and lunged toward another girl with theatrical ferocity.

"Get back here, Bronya!"

The second girl ran with mechanical precision despite the chaos. Her grey hair, tinted faintly blue, was tied into a drill-shaped ponytail that bounced stiffly with each step. She wore a swimsuit that should have looked ordinary, if not for the unmistakable armored prosthetics encasing her legs — sleek, blue, seamlessly integrated into her form. Secondary limbs. Reinforcement. The incongruity was jarring and yet entirely natural to her.

Her expression remained almost perfectly blank as she fled, voice flat and cutting.

"Your intelligence continues to degrade, Kiana. I advise you to reconsider your current course of action."

"Stop running!"

"I will not."

The third figure stood knee-deep in the water, watching with amused detachment. He was tall. Taller than Sunless. Broader in the shoulders. His body bore the subtle signs of someone who had not grown up starving. His hair was the same dark shade. His eyes the same depthless black.

A barcode marked the exposed skin of his neck.

Phantylia stilled.

He was Sunless.

And not.

As the grey-haired girl sprinted past him, he extended a leg with casual timing. She tripped, falling forward with mechanical inevitability.

Kiana pounced immediately, slamming the sea slug against the back of her head triumphantly.

"I win!"

"...Your definition of victory is flawed."

The grey-haired girl stated monotonously as she lay face-down in the water.

The taller Sunny laughed — light, unrestrained, entirely unburdened by hatred.

Something was wrong.

Profoundly wrong.

Phantylia felt it like a tremor beneath her essence. This was not memory. It was not a projection of Sunny’s desire. It was too... autonomous.

"Enjoying the view? I am."

The voice came from behind her.

Phantylia turned.

A teenage girl sat on a blanket laid carefully upon the sand. Her long purple hair was tied into a high ponytail that draped over one shoulder. She wore simple swimwear, modest and unremarkable, as if the grandeur of this impossible dream did not require embellishment. Her posture was relaxed, legs folded neatly to one side, hands resting lightly in her lap.

Her violet eyes regarded Phantylia without fear.

Without reverence.

Without hostility.

Merely acknowledgment.

Phantylia’s glow sharpened slightly.

"Where are we?"

The girl tilted her head faintly.

"You’re in my dream."

The answer was given plainly, without dramatics.

Phantylia paused.

"...This is not his mind?"

"It overlaps. But no. This one is mine."

The Lord Ravager’s presence flickered.

She attempted to probe outward, to find the seams of the construct, to trace the threads of the mind. There were none she could manipulate. The space did not respond to her authority. It did not even recognize her as something worthy of resistance.

It simply existed beyond her jurisdiction.

The girl continued softly, eyes drifting toward the three playing in the sea.

"My homeland. One of my last clear memories of it. An island nation called Japan."

The word meant nothing within the cosmology Phantylia inhabited.

"Never heard of it."

"It doesn’t exist anymore in this branch. Instead, it has a cyberpunk knockoff in the form of Edo Star."

Phantylia froze.

"You are from another leaf?"

The girl nodded once. Phantylia whispered, realization dawning with cold precision:

"A Dream Eater."

Again, a nod.

The girl smiled faintly, still watching the trio in the water.

"Ah. I should introduce them, shouldn’t I? The short one is Bronya. Please don’t tell her I called her that. She’s very particular. She’s smarter than all of us combined. And even though she can’t make a lot of faces, she’s kinder than she looks."

Bronya had managed to shove Kiana off by then, rising to her feet with mechanical dignity while muttering calculated insults under her breath.

"The loud one is Kiana. And, uh... no, she’s exactly as she seems on the surface. What you see is what you get. She’s also kind of my, um... well. It’s a whole thing."

A faint blush dusted her cheeks.

"Then there’s Sunny."

Phantylia’s glow sharpened, listening intently.

"He’s a cross-dresser."

The girl giggled, as if sharing a scandalous secret.

Phantylia did not react.

Her attention had shifted to something far more important.

"You are aware that the boy you are protecting and the one frolicking there are not the same. The Imaginary Tree may have granted them the same Origin, but their existence is fundamentally divergent."

The girl nodded easily.

"I know."

"Then why interfere?"

The girl’s gaze softened, distant.

"This place exists to record my memories of them. The real me is already forgetting their faces. I can feel it happening. But if I don’t anchor them somewhere... they’ll vanish entirely."

She turned toward Phantylia then.

Her expression was calm. Curious.

"Forgive my bluntness. But if you ran into your dead boyfriend in another world after killing his original self’s best friend who happened to be from a post-apocalyptic era... even if they aren’t truly the same person... wouldn’t you want to protect him?"

Phantylia’s radiance dimmed fractionally.

The girl smiled faintly.

"Oh. Sorry. You wouldn’t know anything about that, would you?"

The world shattered.

The golden ocean imploded into darkness. The sky tore open, revealing a vast, starless void. The sand dissolved into black water stretching infinitely in all directions.

Far ahead, a black hole churned — silent, immense, devouring even the concept of light.

Phantylia’s essence recoiled instinctively.

Understanding struck like ice.

Self-Annihilator.

The mark upon Sunny’s soul.

An Emanator of Nihility.

Someone who had endured IX and not dissolved.

The girl stood where the blanket had been, but she was no longer the same.

Her hair flowed freely now, completely white, cascading over her shoulders and obscuring one eye beneath long bangs. The visible eye burned crimson. Thin trails of blood ran down her cheeks, though her expression remained serenely beautiful.

She wore a white kimono that gleamed stark against the darkness. Red oni horns curved from her head, sharp and undeniable. In her hands rested a white sheath etched with intricate purple patterns, cradling a katana that hummed with restrained absence.

"I cannot allow you to violate him any further."

Her voice was neither hostile nor pleading. It was simply factual.

"Either fight him or don’t."

Phantylia felt something she had not experienced in millennia.

Fear.

Not the dramatic fear of imminent defeat. Not outrage. Not anger.

Existential incompatibility.

Her being relied upon Abundance and Destruction. Growth and ruin. Evolution and Devolution.

Nihility was not opposition.

It was negation.

Against it, her existence as a Heliobus unraveled.

Phantylia spoke, the words forced through pride she could not afford:

"...I will withdraw."

The white-haired woman tilted her head.

"Not even a little resistance? But he was getting bored... okay, I guess."

She looked to the side briefly, as if consulting something unseen.

"...I should give her a warning."

The blade slid free of its sheath.

The sound was soft.

Phantylia felt crushing pressure descend upon her existence the instant the katana’s crimson edge was revealed. Lightning crackled along its length — deep red arcs that fractured space itself.

The woman smiled kindly.

"This won’t kill you. Though it will probably hurt a little."

The blade moved.

There was no distance to cross. No wind-up. No telegraphed strike.

Crimson lightning split the void.

Pain erupted.

Not physical pain.

Ontological pain.

Phantylia felt her soul tear loose from Sunny’s body as though ripped by gravitational collapse. Her consciousness fragmented, forced outward through a channel she had not opened. The black sea convulsed. The singularity pulsed once, then receded.

And then—

Reality snapped back.

Sunny was on his hands and knees in the frozen courtyard, mumbling faintly about his sunset.

March was sprinting toward him, eyes wide, fist clenched.

Phantylia hovered in the air for half a heartbeat, her green glow violently unstable.

She did not hesitate.

She fled.

Her essence streaked across the sky, abandoning the battlefield entirely. Across mountains. Across clouds. Toward Scalegorge Waterscape.

Toward a new body.

Behind her, the frozen courtyard remained.

Sunny breathed.

And far beyond perception, in a dark sea orbiting a silent black hole, a white-haired woman calmly sheathed her blade, her hair darkening.

The warning had been delivered.