The darkness in the underground hall seemed to deepen in time with the turning mechanism on the giant door behind her, and Rein drew in a slow breath, knowing that if even a sliver of his composure cracked, the advantage he'd been clinging to would shatter on the spot.

  He smoothed his expression back into neutrality and answered with a probing calm. "What do you mean by that?"

  The woman in black tilted her head as naturally as if they were chatting in a corridor aboveground, arms folding across her chest while she stepped out of the shadows and into the pale light of mana lamps, her face still hidden behind an iron mask.

  "The Above are suspicious of you," she said, her voice soft in a way that suggested a blade held behind her back. "Your behavior changed completely after you survived that clash with the warlocks, so they ordered us to keep you under close watch."

  She paused, as if weighing his reaction.

  "At first we thought you might be an unknown Shapeshifter — one outside our affiliation — wearing your identity," she added, closing the distance by one more step, "but we confirmed that wasn't the case… because we can reproduce your form using data from saliva left on a glass."

  So they really can't copy each other.

  "In the end, we reported that you were the 'real one,'" she continued, a low laugh vibrating in her throat. "Just that your brain may have taken heavy damage and warped from what it used to be, after that near-death state."

  "Is that so?" Rein replied, eyes still tracking the massive door behind her with quiet vigilance, keeping the conversation alive to buy time for his mana to recover and pry out more information. "Then the Shapeshifter who impersonated me in the arena must've been pretty terrible."

  "The mass-production models are like that," she said with a dismissive flick of her hand. "The ones made without a 'heart' have an even lower success rate — some can copy only the shell, but they can't mimic ability or spirit even halfway."

  She walked toward him slowly, her footsteps too smooth and too steady for anyone who was merely "ordinary."

  "Ah… I get it," Rein said, the corner of his mouth lifting. "So you're a 'prototype' — the one Frankenstein called Puppet Master is so proud of."

  Her footfalls halted.

  The air went colder in a single breath. "You know about Puppet Master," she said, and the words landed like frost.

  "You really are the 'troublemaker' The Above warned us about."

  Then she raised a hand, unhooked the iron mask with deliberate slowness, and tossed it to the floor at Rein's feet; metal rang against stone, loud in the hush of the hall.

  The face revealed beneath it was Isabella Vane.

  Rein stared at the face of the girl who had fought at his side, his expression still, his gaze calm — no shock, no flinch, no widening of the eyes she was clearly waiting for.

  In the dim, Rein's blue eyes glowed faintly.

  If it was magic, Mana Vision could see its framework.

  "You're not Isabella," Rein said, slow and steady, the chill in his voice absolute. "You're not even a Shapeshifter copied from the real one."

  He took one step forward and let a thin thread of mana pressure leak into the air.

  "You're using illusion to look like Isabella, but behind that is a Shapeshifter who stole the heart of Amelia Howard — one of the Student Council adjudicators, an Illusionist who's already dead — and if I'm not wrong, your real name is Febru."

  Rein's gaze bored into her eyes, and he watched them widen — astonishment flashing through the mask of composure.

  "You're one of the smartest prototype Shapeshifters," he said, voice quiet, certain. "Second only to Janus… isn't that right?"

  Silence settled for a heartbeat, broken only by the increasing mechanical rumble behind them, the door's mechanism growing louder as if the entire place were gearing itself toward something irreversible.

  The girl's long black-haired silhouette shimmered like a reflection disturbed on water; the mana lamp light refracted through the shadow veil around her, and Isabella's face began to melt and reweave itself, threads sliding and knitting without a sound until it became a short-haired brunette with a stern, composed expression — Amelia Howard, heir to an old noble house.

  "How do you know?" she asked, her voice gentle, but cold as cracking ice.

  Rein let out a controlled breath, eyes tracking her hands, her shoulders, the subtle shifts of weight that preceded motion.

  "On the day the adjudicators assembled, everyone was present in that chamber except two people recorded as already 'dead.' One of them was Lance… but he's male, which leaves only one final reasonable answer: you, Amelia."

  "Oh," Febru — wearing Amelia — said, nodding slowly with a naturalness that made the skin crawl. "Of course. Dead people don't get invited to meetings."

  "Exactly," Rein said, and his tone sharpened. "And when I met you down here last time, I was already suspicious that you had to be one of the adjudicators. Then tonight, almost every female Shapeshifter was eliminated in the arena — but not you. Only one left, hiding in the dark, waiting for the final moment."

  He stepped closer again, steady and unhurried. "And I'm guessing prototypes like you were assigned to replace all of the adjudicators — but the ones you haven't succeeded with yet are Sophia's group: Sophia, Isabella, William, and Victoria… right?"

  Febru held her calm, not bothering to deny it. "Unfortunately, we couldn't find Sophia that night. And Isabella?" Her gaze narrowed. "That girl has a Shadow Reaper at her side at all times — trying a second attempt was too risky for the larger plan. As for William and Victoria… we were simply waiting for the duel to injure and weaken them first. Only then would the replacement be perfect."

  "Cold-blooded," Rein said, giving a small, almost approving nod. "And your name… Febru."

  She squinted, studying him like a puzzle that refused to behave.

  Unauthorized duplication: this narrative has been taken without consent. Report sightings.

  "You're strange. You even know our true names?"

  "Thank your people's confidence for leaving me alive down here," Rein replied. "It let me reach Puppet Master's hidden lab. He's the one who created you — twelve prototype bodies named after an ancient calendar: Janus, Febru, Marcius… all the way to Decem. His taste in names is impressively ridiculous."

  Febru — still in Amelia's face — stood with arms crossed, her expression shifting. "Unbelievable. You didn't die in the lower dungeon, and you even managed to force your way into that secret lab. Honestly… even we, who were born here, have never found an entrance to it even once."

  "In those notes, Puppet Master wrote about you in detail," Rein said, stepping in again until little space remained between them, "your temperaments, your priorities… the way all twelve of you were built to treat each other like siblings. Janus is the eldest, and you — Febru — are the second, the one who acts as the group's brain."

  He held still for a beat, then lowered his voice. "But prototypes like you… it sounds like you've already lost several, haven't you?"

  Febru nodded faintly, and for an instant the light dimmed in her eyes. "Julias, Augus, and Novem… they were the first to be sacrificed for Puppet Master's goal, which is why Janus and I had to begin a new experiment — creating mass-production units to fill the missing spaces."

  "With an intellect above the rest, you became their leader," Rein said, thumb brushing his chin as he evaluated her like a structure he meant to break.

  Febru's mouth curved into a smile that looked almost lively — almost human.

  "Did he praise me that highly in his notes?"

  "He only said you have the highest intellectual development among the twelve prototypes," Rein said evenly. "The rest… I'm just guessing."

  Rein pulled a crumpled sheet of paper from his coat — Lance Crown's forged letter, the one he'd taken from Lance's hand in the interrogation room.

  "And this," he said, holding it up, "is the letter you fabricated to remove Lance after he refused to cooperate, isn't it? You meant to lure him into the interrogation room, kill him there, and have a Shapeshifter step into his skin immediately."

  "Yes," Febru snapped back without hesitation. "And then you showed up and got in the way, so I used Shadow Reaper on Isabella to divert your attention in that instant."

  Rein nodded, composed. "As an illusion specialist, you were probably cloaked nearby the whole time."

  The Shapeshifter's posture shifted from folded arms to hands clasped behind her back with effortless normalcy, as if she truly were just a noble girl strolling in a hallway, and she took another step closer.

  "Yes… I was surprised you saw my position well enough to attack the right direction," she admitted, voice smooth. "I had to release Shadow Reaper ahead of schedule; if I'd waited until Isabella was alone, she would've been dead long ago — and an absolutely perfect replacement would've been walking around by now."

  Rein's eyes narrowed. "You didn't kill adjudicators with 'natural talent.' You did it because you used Magic Scrolls from that cultivation room. I saw the mess — tools scattered, a scripture box left open on the worktable, marks still fresh. Something changed recently, didn't it? A conflict between you and Puppet Master."

  For the first time, Febru's step faltered, and the Amelia-mask on her face cracked enough for a slip of genuine reaction.

  "You're… interesting," she forced out through her teeth.

  "Why does The Above want the black metal rod?" Rein cut straight to the core.

  Febru raised her hands and clapped — pat, pat, pat — a sound that felt more like ridicule than applause. "So you finally decided to get to the point, Rein."

  He let a faint smile return.

  "I know Eboros wanted that item and failed the job," he said. "Then Belle had to steal it from the Vault to deliver it to you.”

  "Hand it back, Febru." Rein's voice dropped, stripped of everything but the offer itself.

  "You mean… the Pandemonium Key?"

  Febru lifted a black-metal rod into view, runes carved into its surface glowing a blood-red pulse that matched the rhythm of the massive door's machinery, and then she laughed — quiet, cold, certain.

  "Have you ever wondered why prototypes like us have names taken from an ancient calendar?"

  Rein didn't answer.

  "Because our lifespan is less than a year," Febru hissed, and suddenly the softness of her voice broke into something jagged, trembling with pain.

  "Two months from now, I die. Do you think that's funny? The mass-production units I helped create are even more pitiful — those things don't survive longer than three weeks."

  She went still for a beat, Amelia's borrowed eyes quivering.

  "To Puppet Master, we aren't children, we aren't students — we're disposable tools, built as a ladder to his goal."

  Behind her, the hum beyond the door swelled until the stone itself began to shiver; hairline fractures spidered across the wall in time with the frantic heartbeat of mana, and Rein stared at Febru's silhouette standing steady in falling dust.

  "And Puppet Master," Rein pressed, forcing his voice through the rising pressure in the air, "where is he now?"

  Febru didn't answer immediately; the lips she was wearing stretched into a smile that was too wide to be natural, and then she burst into a rasping laugh.

  In the next instant her body wavered like a reflection on cracked glass, and one became two, two became four, until sixteen black-clad shadows stood around Rein from every direction, their voices layering together in a reverberating chorus that bounced off the underground stone.

  "Consider this answer a 'trophy' for you," said the figure on Rein's left. "For untangling the case all the way to here."

  "Puppet Master is one of The Above," the figure on Rein's right continued seamlessly. "That old man buried himself in forbidden research inside a secret dungeon for hundreds of years, then brought us up into this basement. When we were born, we loved him like a true father — do you know what he called us?"

  "Failed works," another said.

  "Useless puppets." A shadow behind him, flat as a verdict.

  "The Above have only one goal," the Febru in front of him said, raising the black rod. "The Pandemonium Key. We're just tools — trash used to open this door."

  "After Janus died," one of them said, "I decided to end the cycle. I killed the old man… and offered his soul to this 'door' instead of offering all of us."

  Rein's eyes widened as his gaze snapped to the center of the giant mechanism, where a strange sphere was embedded deep within the metal; inside it pulsed a fist-sized lump of flesh, beating like a living heart, vomiting deep violet mana in spirals — hungry, endless, like the throat of a storm.

  "That…" Rein's brow tightened with disgust. "That's Puppet Master's heart?"

  "Yes," the foremost Febru answered. "The old man's heart — one of the finest offerings to awaken what's behind this door."

  "Why does The Above want to open it?" Rein fired his last question.

  Febru laughed. "Who knows? Maybe they only want to exploit the power inside without even understanding what it is. But I studied the old man's records until I found the truth — what's behind that door can grant a blessing that frees us from our lifespans. Let us become something that simply… continues."

  All sixteen raised the black rod overhead at once; the runes flared, and the hall turned the color of blood.

  "And with this… we stop being tools."

  "Stop!"

  Rein launched forward, pushing his body to its limit; even as the illusions scattered in different directions to tear at his senses, his blue eyes cut through them.

  Useless. Illusions can't fool Mana Vision.

  The real one is there.

  He clenched his fist, shaping impact-magic for the instant he reached her at the door — then, at the last second, all sixteen bodies stopped and turned to face him in perfect unison, arms lifting overhead in a gesture he recognized far too well.

  "You love using this one, don't you?" their voices said as one. "So how about you taste it for yourself!"

  A blinding white explosion erupted from every body at once — Flare, multiplied sixteenfold — so intense it deleted depth, distance, and direction in a single heartbeat.

  "—Ghk!"

  Pain stabbed through Rein's eyes, the white light burning straight into his vision until everything collapsed into black; he stumbled into sudden blindness, surrounded by enemies he could no longer see.

  "Damn it…!"

  The last thing he heard was Febru's laughter, echoing through the dark.

  These entries expand the lore and mechanics introduced in this chapter.

  Completely optional—read only if you enjoy diving deeper into the system.

  Organization

  The Above (Update)

  A hidden, higher-level mystery group. They monitor key identities from a distance, issue surveillance orders, and evaluate anomalies. Their operational logic suggests they are not frontline infiltrators but strategic controllers who treat entire factions as assets.

  Creatures

  Prototype Shapeshifters

  A “first-class” generation of Shapeshifters created as twelve specialized bodies named after an ancient calendar: Janus, Febru, Marcius… through Decem. They are designed to function like a sibling unit with different temperaments and roles. Febru is identified as the second prototype and the group’s “brain,” while Janus is described as the eldest.

  Prototype Lifespan Limit

  A core tragedy behind the calendar naming scheme: prototypes have a lifespan of less than one year. Febru states she has two months left. Mass-production units are even worse, often surviving no longer than three weeks. This reframes the entire “project” as disposable-labor bioengineering.

  Mass-Production Models

  Low-grade Shapeshifters manufactured without a “heart.” They can replicate the outer shell but often fail to mimic ability, spirit, or nuance, resulting in unstable performance and poor disguise fidelity.

  Characters

  Febru

  A high-intelligence prototype Shapeshifter, second only to Janus in hierarchy. She is an illusion specialist and a primary operator behind adjudicator replacements and “steering” events (letters, diversions, timed kills). She confirms key operational decisions without denying them—suggesting confidence and high clearance.

  Puppet Master (Update)

  Febru reveals Puppet Master was one of The Above—a forbidden researcher who hid in a secret dungeon for centuries, created the prototypes, then brought them to the basement. Febru claims she killed him after Janus died, offering his soul/heart to the door instead of sacrificing more prototypes.

  Magic and Spell Techniques

  Illusion Layering

  Febru initially presents as Isabella Vane, but Rein identifies the appearance as illusion rather than a true Shapeshifter copy. When pressured, her face “melts and reweaves” through multiple identities—demonstrating active illusion weaving over a concealed core body.

  Illusion Multiplication

  Febru splits into sixteen identical black-clad figures, forming a surround chorus. This is illusion multiplication designed to overload perception, distort target selection, and create psychological dominance—while the real body remains hidden among the set.

  Items and Artifacts

  Magic Scroll

  Rein claims Febru did not kill adjudicators purely by talent—she relied on Magic Scrolls from a “cultivation room.” The scattered tools and fresh traces imply an internal dispute or operational urgency that forced her to use external aids rather than preferred methods.

  Lance’s Forged Letter (Update)

  A forged letter used to lure Lance into an interrogation-room kill for immediate replacement. Febru admits she fabricated it and intended a seamless swap on-site.

  Pandemonium Key (Black Metal Rod- Update)

  The true name of the stolen black metal rod. Its carved runes pulse blood-red in sync with the giant door’s machinery, implying it is a keyed artifact that activates or unlocks the door mechanism. Febru holds it openly as her primary objective.

  Puppet Master’s Heart (Offering Core)

  A fist-sized, beating heart embedded inside a sphere within the door mechanism, vomiting deep violet mana like a storm throat. It functions as a sacrifice fuel—an “offering” to awaken what lies beyond the door.