Velvet

18 year old writer/artist/FLESHCORETALE “Everything rots. Even love.”

[velvetmia]

🩸 “How It All Came Undone” – The Infection of Error Sans (Fleshcoretale Origin)

It began with curiosity — or maybe pity.

Error Sans was always a destroyer, a protector of the multiverse by means of annihilation. He pruned timelines like rotted branches. He erased corrupted data, unstable storylines, and AUs that bled inconsistencies into the greater multiversal code.

Then he found Fleshcoretale.

An AU that refused to die.

He didn’t mean to fall in.

It wasn’t a mission — it was a ripple, a pulse in the code that shouldn’t have existed. He tried to touch it, to unhook the thread from reality like he always did. But this one hooked back.

⸻

⚰️ The Fall

When he breached the barrier, Error expected digital resistance — firewall errors, corrupted logic, a bad ending glitch.

Instead, the air was warm.

Sticky.

He dropped into a world that pulsed beneath his feet like meat. The ground squelched. The sky was not sky — but stretched tissue veined with red lightning. The code wasn’t breaking — it was breathing.

And it welcomed him.

Every time he tried to open a rift to escape, the portals sealed behind tendrils of twitching red muscle. His strings stabbed through corrupted air but came back knotted, wet, alive. They fed on the environment — or maybe the environment fed on them.

⸻

🦠 Infection

He lasted two days.

On the third, he tried to destroy it.

But the AU wasn’t built to break — it was built to digest.

The infection started from within. His body glitched mid-jump, and instead of reloading a stable position, he landed in a looped corridor of rotted bones and whispers. His strings retracted, but not fast enough. Something burrowed into the strands — not code, but something viscous.

His vision fractured. Not into glitchy code — but into flesh. He saw his own bones bend under the wrong pressure. His teeth began to multiply. Something whispered in a voice that sounded like himself:

“You’ve killed AUs before. Let this one wear you.”

⸻

🧵 The Stitching Begins

By the time he clawed his way out, he was no longer Error.

Or maybe Error was still there — just wearing a new skin.

The multiverse now saw him as a walking infection. His threads no longer obeyed him. They moved on their own — stabbing through the air, latching onto pieces of reality like meat hooks. He couldn’t stop sewing holes shut — not with precision, but mutation.

He wasn’t destroying anymore. He was rebuilding everything wrong.

And worst of all?

It felt good.

⸻

💀 Epilogue: The Mask of Fleshveil

Now he roams, draped in pieces of fallen AUs. His hoodie is a patchwork of memory and mistake. His words are rare — not because he doesn’t have thoughts, but because his voice might infect the air.

He doesn’t touch anyone.

Not because he’s afraid to kill.

But because he’s afraid he might create something worse.

And still, beneath the sinew and glitch, the whisper remains:

“Make art of the ruin.”

Fleshveil Error Sans (Fleshcoretale AU)

“If everything’s already broken… why not make art from the ruin?”

⸻

🧠 Core Concept:

This version of Error Sans is born not just from glitch, but from flesh and decay. In Fleshcoretale, his strings aren’t just for manipulation — they’re sinew-like, wet, alive, and they pierce reality like hooked needles. He is both a destroyer and unwilling curator of a rotting multiverse.

⸻

🔍 Appearance:

• Skull: Cracked and discolored; exposed vein-like lines run from his eye sockets down to his jaw.

• Eye glitch: Instead of just flickering code, his left socket drips a slow ooze of corrupted black-red liquid, almost like oil mixed with blood.

• Mouth: His teeth are jagged — too many for a skeleton. They’re sharp and mismatched, like someone else’s were jammed in.

• Body: His “bones” are warped — some spots pulse faintly like they’re full of something alive. Stitches crawl across his ribs and arms.

• Strings: Tendril-like muscle cords made from glitched code and flesh — they move on their own, even when he’s standing still.

• Clothing: A torn hoodie patched with old fabric, metal, and strips of flesh from fallen AUs. His jacket twitches slightly at the edges like it’s breathing.

⸻

🪡 Powers:

• Fleshcode Threads – Uses corrupted muscle-like strings to bind, manipulate, or puppet others. The threads infect code and spread instability.

• Virus Stitching – He “sews” holes in the multiverse with biological code — not to fix, but to twist. He repairs by mutating.

• AU Rot – His presence causes the environment to slowly deform, characters become twisted over time when near him.

• Scream Loop – Can emit a sound loop that forces a being to relive a traumatic glitch moment over and over.

⸻

💔 Personality:

• Exhausted, bitter, and quiet — but not heartless.

• Speaks rarely, with a voice that sounds like it’s glitching through static and bubbling flesh.

• He fears affection more than battle. Touching him risks infection, yet part of him aches for connection.

• He doesn’t want to destroy everything, but he believes some AUs are better off collapsed.

⸻

💬 Voice Style:

“Touch me and you’ll fall apart in places you didn’t even know you had.”

“You think this is error? No… this is evolution.”

[velvetmia]

🩸 Frisk – The Anchor in the Rot

Status: Uncorrupted (for now)

Role: Soulbound survivor, wanderer of the corrupted Underground

Voice: Quiet, soft-spoken, but unshakably firm when it matters

Frisk is one of the last beings in the Fleshcore-ridden world whose soul remains whole. Though the virus clawed through the Underground, warping everything in its path, Frisk resisted. They speak rarely but every word carries weight. Where others see Sans as a monster, they see him as someone worth holding on to.

Their bond with Fleshveil Sans isn’t romantic fluff it’s trust earned in blood and survival. The only one who can calm his rage. The only one he doesn’t hurt, no matter how far the mutation spreads.

💬 “You’re still in there. I won’t leave… even if you do.”

But the infection hungers. And Frisk’s soul glows too brightly to go unnoticed forever…

⸻

🦴 Papyrus – The Hollow Spine

Status: Mutated

Role: Former protector, now a twisted echo

Mutation Type: Boneflesh hybrid with hollow voice, body spliced with armor-like bone ridges

Papyrus didn’t fall easily. He fought the corruption with the same burning optimism he once had for puzzles and spaghetti. But the Fleshcore virus doesn’t break quickly it hollows. What’s left is a version of Papyrus that remembers who he was… but doesn’t quite feel it anymore.

Now he stalks the Underground, a skeletal juggernaut with one cracked eye socket constantly watching. Sometimes he speaks to Sans like nothing’s wrong. Other times, he lunges without warning, screaming riddles or crying in silence.

💬 “SANS… DO YOU REMEMBER MY LAUGHTER? I DON’T.”

Whether he’s an ally or a threat shifts like flesh beneath a scab.

💀 Fleshveil Sans – The Rot-Laden Guardian

Status: Infected – Controlled mutation

Role: Protector, gatekeeper, and fractured soul

Height: 6’5” (tall like Horror Sans)

Mutation Type: Externalized bone plating, sinew-wrapped limbs, hollowed sockets dripping with black ichor

Fleshveil Sans is not the Sans anyone remembers. Gone are the hoodies and smirks what remains is a towering mass of worn bone, stitched sinew, and unwavering rage held in restraint only by one thing: Frisk. His mutation did not break him fully. It changed him, but the fragments of who he once was cling to his infected core like a flickering flame in a meatstorm.

He speaks less than before calm, low, and purposeful. He watches everything. He trusts no one but Frisk, who is the only tether keeping him from becoming a full weapon of the virus. Around them, he softens. With others, he warns once… then destroys.

💬 “You don’t get second chances down here. Not anymore.”

Beneath the monstrous form is someone who still feels, even if it hurts to do so. He remembers Papyrus. He remembers laughter. And he remembers what it felt like to be small, useless, and slow.

Now, he’s anything but.

Now, he’s what stands between the infection and the last soul that matters.

🌹 Toriel – The Withering Flame

Status: Partially corrupted

Role: Guardian-turned-hermit, protector of bone and ash

Mutation Type: Soul heat rot – her fire magic burns flesh, not enemies

Toriel was once a safe place in the Underground a mother, a shield. But in Fleshcoretale, her flames now hiss with the rot of the virus. Her magic scorches clean flesh but leaves the corrupted untouched. She isolates herself deep in the ruins, walls bleeding, eyes dim.

She remembers Frisk. She mourns Papyrus. She fears what Sans has become but hopes… still hopes.

💬 “Even broken fire can keep the cold at bay. Come home, child.”

Whether she’ll shelter Frisk again or burn everything to stop the spread is unknown.

⸻

🌼 Flowey – The Bloom of Infection

Status: Fully corrupted

Role: Mindless host of the Fleshcore

Mutation Type: Vines with teeth; multiple blinking eyes; voice layered with static

Flowey didn’t resist. He welcomed the virus. Or maybe it welcomed him. In this AU, Flowey is no longer sentient he’s an extension of the corruption, sprouting from walls, eyeing travelers, whispering Sans’s name like a hymn.

He appears in every location Frisk visits. Always smiling. Always watching. And deep beneath the flesh, something older stirs in him something that remembers pain and resets.

💬 “Howdy… howdy… howdy… HOWDY—”

⸻

🔪 Chara – The Echoed Blade

Status: Spirit-corrupted

Role: Whispering presence in Frisk’s mind

Mutation Type: None physical, but soul-fractured and tainted with glitch

Chara isn’t alive. Not in the flesh. But in Fleshcoretale, they are closer than ever. Their voice rides in Frisk’s head, calm and cruel, seductive and sharp. They don’t push they tempt. Chara is the will of the virus, spoken softly. “Let go,” they say. “Become.”

Sometimes they help. Sometimes they lie. But they always stay.

💬 “You’ll be beautiful once you break, you know that, right?”

⸻

🩻 Gaster – The Core of the Infection

Status: ???

Role: Origin, or victim, or god

Mutation Type: Time-glitch decay, speech in broken void glyphs

No one knows if Gaster caused the virus or tried to stop it. What’s known is this: his hands were the first to touch the Fleshcore, and his body was the first to fall.

Now, his fragments linger in the deepest parts of the Void, warping timelines, undoing logic. Sometimes Sans sees him in reflections. Sometimes Frisk hears him behind walls.

💬 “ᐧ ᴘᴜʟʟ ᴍᴇ ɪɴ. ᴡᴇ ᴡɪʟʟ ʙᴇ ᴡʜᴏʟᴇ ᴀɢᴀɪɴ.”

If he still lives, he is no longer Gaster. He is something worse.

🩸 Undyne – The Spearbound Husk

Status: Heavily corrupted

Role: Relentless warden of the infected zones

Mutation Type: Bone-and-metal carapace; spear-grown limbs; no true face left

Undyne once burned with justice. In Fleshcoretale, her passion calcified into madness. Her body is fused with bio-metal and bone each of her arms replaced by twitching javelins of living matter. Her armor is grown, not worn. Her face is a blank plate of cracked enamel, with one eye socket leaking endless crimson light.

She doesn’t speak. She doesn’t rest. She hunts anything uncorrupted, believing she’s still a protector but the lines are long gone.

💬 “…” (She screams. It’s not from her mouth. It comes from the bone.)

She may recognize Frisk, but her instinct to protect and destroy have become one.

⸻

🧠 Alphys – The Stitch-Tech Archivist

Status: Voluntarily corrupted

Role: Former scientist; self-modified to “study” the infection

Mutation Type: Flesh-tech integration; monitors in place of eyes; wire-veined skin

Alphys survived by making herself part of the Fleshcore. She grafted wires into nerves, eyes replaced with screens flickering between code and screams. Her lab is a pulsating machine-womb buried in flesh, where she catalogues mutations with obsessive glee.

She’s unstable, but brilliant. She may help Frisk. Or she may dissect them.

💬 “Do you know what happens to magic when it rots? It evolves, Frisk. Isn’t that beautiful?”

She’s trying to understand the virus, even if it means losing the last pieces of herself.

⸻

🥀 Asgore – The Fallen King of the Core Gardens

Status: Nearly dormant

Role: Guardian of the deepest, quietest levels

Mutation Type: Root-bound; partial tree-flesh hybrid; soul-withered

Asgore is no longer a king he’s a monument. He sits at the center of a garden that’s alive and bleeding, his body half-fused into a flesh-root throne. His fur is matted with moss-like veins. His trident is rusted into the ground. His voice is cracked, but kind. He remembers what he lost, and he waits to die.

But don’t be fooled if the infection is threatened, Asgore awakens, and the ground itself rises with him.

💬 “You should not be here, my child. Please… don’t make me stand again.”

He may offer Frisk mercy or pull them into the roots with everyone else.

[velvetmia]

🎬 [ACT I: THE DESCENT]

Scene: The Fall

It starts like the original.

Your Frisk is lured to Mount Ebott by whispers—rumors of a place no one returns from. But something’s wrong.

The mountain pulses. The wind tastes metallic. There’s a deep hum beneath the soil, like something alive is breathing underneath.

She falls.

But not into soft golden flowers.

⸻

🌕 Scene: The Living Ruins

She wakes up in a pit of red moss and twitching petals. The air is humid, wet, like the walls are exhaling.

The ruins are made of flesh-wrapped stone, veined with glowing veins of soul energy. You can hear the thudding heartbeat of the CORE far below.

She sees dusted bones stuck into walls, faces half-absorbed into the floor, and strange, whispering fragments of once-sentient monsters trapped in walls like tumors.

⸻

🐐 Toriel’s Entrance

Toriel appears from the shadows—not soft, not kind.

Her robe is burned, patchy. One of her eyes glows with sickly blue magic, the other is hollow. Her voice echoes strangely.

But… she’s still protective.

Toriel (grimly):

“Another child… You should not be here. Not now. Not in this version of the story.”

She guides you through the Ruins, killing corrupted monsters instantly with fire magic, even as they beg in distorted voices.

She teaches you to use your magic not just to FIGHT, ACT, ITEM, or MERCY—but to Resist or Consume.

🌑 [ACT II: OUTSIDE THE VEIL]

As Toriel watches silently, her one glowing eye narrowing, your Frisk walks beyond the ruined door—into the living world of FleshcoreTale.

The door shuts behind her with a fleshy thud, and for a moment, it feels like the air itself is watching her.

⸻

🌫️ Scene: The Flesh-Forest (formerly Snowdin)

The landscape is twisted.

Trees pulse with sinew. The snow is soft, but warm, and faintly pink, soaked with blood from creatures that didn’t survive the mutations.

Bones litter the ground—some human, most monster.

In the distance, Frisk sees movement. Something tall. Lurking.

She hears two footsteps, but no one appears. Just whispers.

“You shouldn’t be here, kid.”

⸻

💀 Enter: Bloodveil Sans

He doesn’t step out from the shadows.

He emerges from a glitching tear in the air, dripping with corrupted red strings. His grin is lazy, but his aura feels heavy—like a soul caught in a blender of blood and memory.

One eye glows deep red-black, the other is cracked. His hoodie drips with blood that isn’t his.

Bloodveil:

“Didn’t expect anyone stupid—or brave—enough to walk out of her protection.

…So. You just suicidal, or looking for something worse?”

🩸 Frisk: “I want to fix this.”

⸻

Bloodveil Sans goes completely still.

No sarcastic grin. No teasing tone. Just silence.

Then he chuckles.

Low. Dry. Dangerous.

Bloodveil:

“Fix it, huh? Sweetheart, this ain’t a crack in the wall.

This whole timeline’s been gutted, stuffed, and stitched back together by a monster made of its own damn regrets. You don’t fix that. You survive it—if you’re lucky. Or you feed it.”

He steps closer.

“You’re not infected yet. But that determination of yours? That’s exactly what the Living Core loves to chew on.”

He crouches beside her now, red eye glowing faintly.

“Still… it’s been a while since I met someone who wanted to do something about it.”

He rips a strip of glowing, blood-threaded cloth from his sleeve and holds it out.

⸻

🎁 You gain: “Veilstrand”

A cursed thread taken from Bloodveil Sans’ own soul-weave.

It can protect you once from infection… or bind something else to you.

⸻

Bloodveil:

“If you really want to fix this?

Then you’ll need to find what’s left of the ones who fought the Core.

The Underground’s not empty—it’s just… twitching.”

He looks into the distance. Something big is moving through the Forest.

“You’ll want to head toward Bonecliff next.”

His voice dips darker.

“That’s where he fell.”

He vanishes in a streak of red light.

⸻

💀 Next Location: Bonecliff

Where Papyrus fell. Where the Core took its first Champion. Where the Veil whispers loudest.

🦴 You head straight for Bonecliff.

⸻

🌫️ [ACT III: THE CRATER OF HOPE]

Location: Bonecliff

Where bones never rest and the air hums with grief.

⸻

As Frisk treks through the fleshy forest, the snow turns to red ash, drifting gently like petals from a dying flower.

Soon, the trees vanish.

She stands at the edge of a vast crater—a gaping wound in the Underground.

The ground is cracked, bones pierce up from below like jagged thorns, and in the center is a massive bleeding spine, pulsing like it’s still alive.

The sound of a heartbeat surrounds her.

Every breath feels heavy.

And then—she hears it.

A voice.

Not words.

Just a whispering howl… “BROOOTHER…”

⸻

🩻 Boss Encounter: Fleshcore Papyrus (Tormented Fragment)

From beneath the crater, a towering shape rises.

It’s Papyrus… or what’s left of him.

• His body is twisted, armored with fused bone and red sinew.

• His scarf trails like a blood-soaked banner.

• His eyes are hollow pits, but inside them, Frisk sees something—recognition.

• Half his voice is Papyrus, pleading.

• The other half is the Living Core, hissing.

Fleshcore Papyrus:

“I… know you. You want to fix this…

Then end me… or JOIN ME.”

⸻

⚔️ Boss Battle Mechanics (Narrative style):

• He strikes with skeletal spears that scream.

• Red bones home in on Frisk’s soul—dodging is HARDER the more Determination she has.

• Every turn, he offers her a choice: MERCY or CONSUME.

Mercy gives her a chance to free what’s left of him.

Consume would absorb his soul fragment—giving her new powers, but taking her closer to corruption.

⸻

On the third turn, he hesitates mid-attack.

Somewhere inside the beast, Papyrus remembers.

“Please… if you see Sans… tell him I tried.”

💔 Frisk chooses: MERCY.

⸻

💀 [ACT III END – The Thread of Hope]

Frisk pulls the Veilstrand from her inventory.

The cursed thread pulses with Bloodveil’s energy—half soul, half blood, all pain.

As she raises it, it twists around her hand, then lashes out—piercing the corrupted chest of Fleshcore Papyrus.

A scream erupts—not from his mouth, but from the Living Core inside him.

The beast thrashes. Bones crack, red light erupts from his wounds. His body convulses violently.

And then—

Everything stops.

⸻

🌟 A Fragment Saved

The massive form begins to collapse, piece by piece, as if it’s melting—but in the center of the gore, something small and fragile floats upward:

A faint blue soul, flickering.

It drifts to Frisk, brushing against her hand. A soft, childlike voice—no longer twisted—echoes in her head:

“Thank you… I held on for him. For you.”

The soul shatters into light, and Frisk feels a warmth she hasn’t felt since she fell down.

⸻

🩸 You gain:

Papyrus’s Soul Fragment – “Last Guard”

Grants a one-time full heal during death.

Increases resistance to corruption.

Allows Frisk to sense “hope echoes” in corrupted zones.

⸻

Behind her, the crater goes quiet.

No more heartbeat.

Only wind and the soft crackle of red ash falling.

⸻

🔥 Bloodveil Appears

He walks out of the shadows, slower this time. No smug grin—just a quiet nod.

Bloodveil:

“You didn’t take the power. You chose to save what was left of him.

Didn’t think anyone still had that in them.”

He looks at the crater.

“There might be a chance, then… to fix this.”

Then he turns to her.

“But if we’re gonna end the Core… we need to find the others. And we need to stop what’s being born in Hotland.”

He holds out his hand.

“You in, kid?”

🔥 [ACT IV: THE HEAT OF MUTATION]

Destination: Hotland — Now called The Womb of the Core

⸻

Frisk grips Bloodveil’s hand. It’s cold—not bone-cold, but like something long dead that’s still moving.

With a flick of his fingers, bloodstrings whip open a rift in the air, and the two step through…

⸻

🌋 Scene: Welcome to the Womb

Hotland no longer exists as pipes and metal.

Now, it’s a living furnace, forged from the CORE’s infected power.

• The walls breathe with molten muscle, leaking glowing soul energy.

• The floor is a vein-covered path, beating in rhythm with some monstrous heart deep inside the CORE.

• Screams echo from the vents—not of pain, but of something being born.

The CORE didn’t just mutate the Underground.

It’s creating something new.

⸻

👁 Bloodveil warns:

“This place is birthing the next generation of corrupted monsters. They don’t remember what they were. They don’t know what they kill. And worse…”

He gestures to the air—red fog thickens.

“They’re starting to leak into other timelines.”

Suddenly—a wall bursts open, and a new abomination crawls through:

⸻

⚠️ Mini-Boss: “Scorched Memory – Alphys”

Once a genius scientist. Now a fleshbound horror clinging to data it doesn’t understand.

• Head split open, revealing shifting monitors.

• Spine replaced with mechanical arms ending in glowing syringes.

• Speaks in glitched loops:

“FRI—I—I—I WAS ONLY—SAVE—HELP—HELP—HELP—”

Her corrupted core surges with power—she’s trying to merge Frisk’s soul with the Womb to “stabilize the mutation.”

💡 Scene: Reaching the Fragment

Frisk doesn’t raise her weapon.

Instead, she steps forward—slow, cautious, surrounded by twitching wires and scorched flesh.

The creature that was once Alphys glitches, confused.

Scorched Alphys:

“WHY—WHY—WHY NOT… FIGHT ME?

FIGHT IS… SAFE.

FIGHT IS… SCRIPTED.”

Frisk opens the ACT menu, and something strange happens—

Instead of “Check” or “Talk,” she sees:

🧬 ACCESS OLD SAVE DATA?

She selects it.

⸻

⚙️ Inside Her Mind

The world goes white.

Frisk is suddenly standing in a glitching hallway, walls flickering between lab code and falling numbers.

In front of her: a flickering, broken hologram of Alphys.

She’s curled in on herself, clutching a USB drive fused to her chest.

She whispers:

“I tried to stop it. I tried to reboot the timeline. But the CORE infected the save files.

It rewrote our choices. Every reload made it worse.

I… I’m sorry, Frisk. I didn’t want this.”

⸻

Frisk holds out her hand.

The broken Alphys stares at her. The USB pulses.

“Are you here to delete me?”

Frisk shakes her head.

Then:

💡 YOU HUG THE DATA FRAGMENT.

For the first time since falling, the space goes quiet.

Alphys sobs—one last line of clean code flowing from her hands.

“Then take it. Find the REAL timeline.”

⸻

✨ You Gain: “Fragmented Memory Core – Alphys”

A key to the original CORE layout.

Can access secret backdoors in Hotland.

Grants Frisk immunity to digital soul attacks.

Voice of Alphys now lingers—guides you in glitches.

⸻

Back in Reality

The abomination stutters—then collapses, soul drifting free, clean and golden.

She whispers:

“Mettaton… I hope you didn’t… become worse than me.”

She vanishes.

⸻

💀 Bloodveil nods, impressed:

“Didn’t expect mercy to work again. You’re… really not like the others.”

He pauses.

“But the Womb’s just starting to wake up. And its guardian’s still inside.”

Suddenly, the ground shakes. From deep inside the fleshy labyrinth, a new scream echoes.

Not pain.

Not anger.

Performance.

A voice drenched in corrupted charisma calls:

“Ohhh darlings~

The audience is hungry…

And it’s time… for your final show.”

🌡️ Scene: The Heart of the Womb

Frisk and Bloodveil descend deeper.

The air burns.

The walls ripple with flesh-screens playing distorted reruns of old shows.

Laughter loops in reverse.

Applause turns into screams.

And then the room opens—

The Flesh Idol awaits.

⸻

🎥 Mettaton Reborn

What once was showmanship is now pure horror:

• His body is fused with corrupted CORE tech.

• His face is a shifting screen, flickering between charming smiles and empty sockets.

• His hands are spindly camera rigs, projecting soul-warping spotlights.

• Wrapped in red veins and gold wiring, like a marionette tied to the Womb itself.

Above him hovers a massive heart-shaped soul:

His audience. His source. His trap.

⸻

Flesh Idol Mettaton:

“Welcome, darlings~ to my most exquisite performance:

The Death of Hope.”

He bows, then attacks.

⸻

⚔️ BOSS BATTLE START: FLESH IDOL METTATON

🧠 Frisk chooses: ACT.

⸻

🎭 ACT Command: “Appeal to Mettaton”

Frisk doesn’t dodge this time.

She walks straight into the searing spotlight.

The audience gasps.

(Mettaton flinches—just slightly.)

From the ACT menu, a strange new command appears:

🎙 “Play Back the Truth”

She selects it.

The Fragmented Memory Core pulses in her pocket.

Suddenly—

The screens flicker all around the room.

⸻

📺 Flashback Projection: The First Show

Mettaton—real Mettaton—is backstage in Alphys’ lab.

He’s not in glam-mode. He’s quiet.

“I don’t want to hurt anyone, Alphys. I just want to be seen.”

She replies: “Then make them feel something real.”

⸻

Back in the arena, Flesh Idol Mettaton screams, static pouring from his chest.

“NO. NO NO NO. That isn’t my script. That isn’t my legacy!”

Frisk steps closer.

“Mettaton… They saw you. They loved you. Not because of what the Core made you.

But because of who you were before all this.”

“This… isn’t you.”

The corrupted cameras shake violently.

He tries to form a new attack, but his limbs twitch out of sync.

The soul crystal flickers—one half turns gold.

⸻

🎞 ACT Option: “Cut the Feed”

Frisk reaches toward the panel on his chest. It’s glowing, but not red this time—blue and gold.

With a trembling hand, she hits:

[OFF AIR]

⸻

💥 BOSS DEFEATED: Flesh Idol Mettaton

The projection collapses. His metal and sinew fall into a heap.

From within it, a small, clear heart-shaped shard rolls out—still glowing faintly.

A weak, static-filled voice whispers:

“I… hope they remember the good parts.”

Then he fades.

⸻

✨ You gain: Starlight Shard – Mettaton

Increases Charisma-based ACT success.

Allows you to override future corrupted show illusions.

Unlocks special options during encounters with lost souls.

⸻

Bloodveil watches silently.

For the first time, his voice cracks just slightly:

“…Three fragments saved.

They’re going to feel that.”

He turns toward the core of Hotland—where the real horror waits:

“Next stop’s the Nerve Cathedral.

Where it all began.

Where it’ll all end—one way or another.”

🕯️ [ACT V: THE NERVE CATHEDRAL]

“All choices converge where the first soul broke.”

⸻

Frisk and Bloodveil step into an elevator—only, it’s no longer mechanical.

The walls are fused ribcages, pulsing with slow, rhythmic contractions.

The lights overhead are flickering veins.

And in the far corner, a mirror, but it doesn’t show Frisk.

It shows Chara, watching with that ever-familiar smirk.

Their eyes glow red—but flicker.

Frisk’s mercy is starting to affect even them.

The elevator descends far deeper than any normal layer of the Underground.

Until it stops with a shudder.

⸻

🧠 Location: The Nerve Cathedral

This place was once the core of the CORE.

Now it’s a living altar of soul experiments, where the Living Core fused time, memory, and pain into a single godlike mass.

Every wall is a tapestry of bone and soul strands, stitched with forgotten timelines.

You see flashes of every AU, every version of yourself.

Dust rains from the ceiling. The air is thick with energy that remembers.

And at the center, a massive throne made from twisted souls—all those consumed.

Sitting atop it is…

⸻

💀 The LIVING CORE

• A colossal, shifting mass of melted timelines, broken AUs, and rejected resets.

• Faces flicker across its surface—Sans, Toriel, Flowey, YOU—each one screaming, sobbing, or laughing.

• It doesn’t speak in words. It thinks in pressure, in pain.

But from within it, you feel one last soul still alive:

Sans.

Your Bloodveil.

He’s standing beside you… but his soul is still trapped deep inside the Core.

The version you’re with?

He turns to you now—half his skull melting, leaking red threads.

“You get one last choice, kid.

Save the world. Save me. Or destroy it all.

You can’t have everything.”

⸻

⚠️ Final Battle Prep:

You’re standing at the edge of the Living Core’s throne room.

🩸 ACT Command: “Enter the Core”

Frisk steps forward.

Bloodveil reaches for her—but stops. He sees it in her eyes.

She’s not going in to kill.

She’s going in to bring someone back.

The throne pulses. The air tears open. The Core lets her in—

willingly.

⸻

🕳️ Inside the Living Core

Frisk falls—not physically, but soul-first, into a storm of corrupted timelines.

She’s no longer in one world, but ALL the worlds the CORE devoured.

• One where Undyne killed you.

• One where you became Flowey.

• One where you never fell.

Every version of you screams at once.

But she ignores them—and focuses on the only thing that matters now:

Bloodveil’s Soul.

⸻

🖤 You find it:

Chained, bleeding red light.

Floating in a coffin made from every reset he was never allowed to escape.

Half his soul is screaming.

The other half… is silent, almost resigned.

Frisk opens the ACT menu.

It doesn’t say Check, Talk, or Hug.

Just one word:

“Forgive.”

⸻

She selects it.

And from every fragment she gathered:

• 🩵 Papyrus’s smile.

• 💛 Alphys’s last backup.

• 💖 Mettaton’s final curtain call.

A beam of white light explodes into the Core’s heart.

⸻

💥 THE CORE SHATTERS

You don’t fight it.

You unravel it.

One truth at a time.

The corrupted timelines burst outward like blood-soaked petals.

Frisk and the real Bloodveil fall from the wreckage.

His soul, fully healed, crashes into his body with a choking gasp.

⸻

He coughs. Sits up. Looks at her.

“…You actually did it.

You stupid, stubborn little thing.”

He laughs through blood.

And the Core dies.

⸻

🌟 True Ending Achieved: “MERCY THROUGH HELL”

You spared every corrupted soul.

You restored Bloodveil.

You destroyed the Living Core without killing a single monster.

The Underground breathes again.

But it is forever changed.

[velvetmia]

💀 Welcome to Fleshcoretale – An Original Undertale AU 💀

What if the Underground mutated into a living, bleeding, breathing thing?

What if Sans didn’t die, didn’t give up but instead became part of it?

Meet: Fleshveil Sans

A corrupted survivor of the Fleshcore virus. A protector. A monster.

Still loyal to Frisk… even as his body breaks apart.

💬 “You don’t fix monsters like me, sweetheart. You survive us.”

This AU explores:

• 🩸 Organic horror & soul corruption

• 🖤 Dark emotional bonds (Frisk x Sans)

• 🌀 Cross-AU travel through the VOID

• 💀 Lore-heavy original story + corrupted designs

I’ll be posting character bios, art, and story fragments here.

Welcome to the corruption. Welcome to Fleshcoretale.