Chapter 18: Shadows in the Halls

The sun rose sluggishly over Star Academy, its golden light barely piercing the heavy clouds that loomed above the artificial island. Within its vast stone halls, the atmosphere had shifted. A quiet tension gripped every corridor and classroom. Students whispered, rumors spread, and even the teachers seemed more reserved than usual.

Lee Yujin, Kain Vagor, Mira Kisaragi, Sylvia Estelle, and Taro Blaze had been chosen for a mission unlike any they'd faced before. Unlike dungeons or virtual combat zones, this mission required subtlety, perception, and patience. Their task was to investigate the faculty themselves—to find which professors had been corrupted or replaced by disguised demons during the recent dungeon break and realm crack incident.

In the war room just beneath the academy's main tower, the cadet squad gathered in silence. Arcan Ludien had given them the initial list: six professors with suspicious behaviors logged over the past three months. Among them were Professor Rendal—known for his fire-element lectures, Professor Hohen—the quiet summoner of beasts, and Professor Elira—once an esteemed healer who now seemed cold and distant.

"This isn't a battle of strength," Kain said, crossing his arms. "We need to use our minds for once."

"Speak for yourself," Taro muttered, cracking his knuckles. "I still think brute strength solves everything."

Sylvia smirked, "Don't worry, Taro. If someone needs to be knocked out quietly, we'll count on you."

Yujin, however, wasn't joking around. His eye-based ability—Divine perception and a side-effect of the Demon Howl gun and allowed him to perceive flickers of mana irregularities. And he planned to use it.

Their plan was simple: split into pairs, rotate classes, and monitor behaviors without raising alarms. Over the next three days, they spread out—Sylvia and Mira took Elira's healing theory classes, while Yujin and Kain observed Rendal and Hohen during afternoon lectures.

What they found was disturbing.

Professor Rendal, once passionate and sharp, now taught without emotion. His once-flaming aura had dimmed, replaced by unstable bursts of red-black mana only visible to Yujin's enhanced vision. He would often mispronounce spell incantations he'd taught for years. His eyes were glassy, and once, Yujin caught him staring into space, murmuring ancient words in a forgotten tongue.

Meanwhile, Professor Hohen's familiars—a wolf, a hawk, and a snake—had begun to act strangely. The hawk, once obedient, attacked a student without provocation. Kain noticed the professor's shadow moving on its own, flickering like something alive. Sylvia later confirmed her suspicion—his mana signature had a hidden second layer. It was a demon aura cloaked under illusion magic.

During their third day, Mira followed Professor Elira into the restricted archive. Hidden with her mother's assassin skills, she overheard Elira speaking to a mirror—no reflection, only a black void responding in guttural sounds. When Elira turned, her irises momentarily flickered crimson.

That night, they all met in Yujin's room and laid their findings on the table.

"There's no doubt," Sylvia said. "All three are compromised."

"But only Elira is fully turned," Yujin corrected. "Rendal and Hohen might still be suppressing it."

"We need proof. Solid evidence," Mira said. "Or else the higher-ups might think we're paranoid."

Kain leaned back, fingers tapping the hilt of his sword. "Then we give them proof. Tomorrow. We confront them."

The plan was risky, but necessary. They baited the professors into an isolated duel simulation chamber—one that only senior faculty had access to. Sylvia hacked the access with her brother's code, and the five cadets lured the three into it with forged messages.

Inside the chamber, the moment the doors shut, everything changed.

Professor Elira's form twisted, her once-elegant robes burning away to reveal a scaled body and fanged smile. "You children... you've meddled too far."

Rendal groaned, clutching his head, but his eyes darkened. "I... can't stop it…"

Hohen silently summoned a massive black wolf with glowing eyes, but its shadow merged with his feet.

"We're fighting all three," Yujin said coldly, drawing Demon Howl.

Kain unsheathed Phantom Blade. "Let's put them down."

The battle was swift, but fierce. Taro went toe-to-toe with Hohen's beasts, his brute strength smashing through barriers. Mira darted through shadows, cutting Elira's joints with surgical precision. Sylvia unleashed a barrage of spear thrusts with explosive magic, keeping Rendal at bay.

Yujin activated his Divine Vision, and time seemed to freeze for him. Every weak point of the enemy shone in glowing blue. He struck Elira's heart core, shattering the disguise and revealing a shrieking demon underneath.

With a synchronized final strike, Kain and Yujin cleaved through Hohen and Rendal, purging the demon essence without killing the hosts.

As they stood in the aftermath, a notification flashed in Yujin's vision:

> Mistake Solved 6: Demon infiltration within Star Academy.

Yujin narrowed his eyes. Another mistake corrected. But what other secrets lay behind the remaining 44?

For now, they had won.

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