A Korean transmigrator who spent thirty uninterrupted years fighting on the front lines of the demonic war, Kim Seonwoo shed his civilian identity to become Ivan Petrovich, former Lieutenant Colonel of the legendary Annihilation Unit. Exhausted by decades of slaughter, his singular desire was a peaceful retirement operating an orphanage in the Krasilov borderlands. Ivan operates with extreme tactical pragmatism, viewing combat through the cold lens of resource management, threat elimination, and survival doctrine. Emotionally detached yet fiercely protective of civilian life and vulnerable children, he treats the reappearance of game tropes and system anomalies not as heroic opportunities, but as systemic security hazards requiring brutal counter-insurgency tactics. Powers: Master of military-grade mana infusion, tactical firearm marksmanship (specializing in pistol sniping and suppressive fire), and brutal close-quarters assassination techniques. Possesses thirty years of anti-demon and anti-mage combat experience, high-level pain tolerance, psychological warfare mastery, and ruthless interrogation protocols.

Revered and feared across the realm as "Iron-Blooded Liza," Princess Elizaveta is the calculated, unyielding political mastermind of the Tsardom of Krasilov. Realizing that the fragile peace won thirty years ago is rapidly unraveling under foreign espionage and domestic treason, she leverages state authority without sentimentality. Elizaveta recognizes Ivan’s lethal utility as a veteran weapon rather than a mere soldier, deploying him into Saint Yansk University as an off-the-books apex predator to safeguard the realm's next generation and maintain royal dominance over rising factions. Powers: Imperial political authority, intelligence network orchestration, high-tier royal tactical education, and access to state-level magical artifacts and state treasury resources.

An ancient elven vampire rogue and an original member of the Legendary Hero Party that slew the Demon King thirty years prior. Beneath his nonchalant demeanor and eccentric cover as a guest lecturer and underground information broker at Saint Yansk, Enrique harbors the world-weary vigilance of an immortal survivor. He respects Ivan’s lethal battlefield efficiency and acts as his senior operational supervisor within the academy, balancing covert underworld intelligence with the protection of his personal disciple. Powers: Ancient Elven shadow arts, vampiric physical enhancement, covert infiltration, master-tier espionage networks, and high-speed lethal blade techniques honed over centuries of active combat.

The noble daughter of the late Legendary Hero Maximilian, Isabelle carries the immense psychological weight of her bloodline's legacy. Entering Saint Yansk University as a prized freshman, she is fundamentally unprepared for the dark political conspiracies and assassination attempts orchestrated to eliminate the descendants of the Hero Party. Targeted during the fatal train ambush, her survival hinges entirely on Ivan's shadow warfare, setting her on a path of rapid maturation from an innocent heiress to a vigilant combatant. Powers: Inherited radiant holy aura potential, foundational noble sword arts, and latent anti-demonic lineage abilities passed down from the Hero Maximilian.

A modern Earth transmigrator who was thrust into the fantasy world equipped with a gamified "System" and designated quest interface. Conditioned to view the world as a scripted RPG tutorial, Eugene’s naive confidence is violently dismantled when his quest to orchestrate an academy incident is intercepted, dismantled, and forcefully canceled by Ivan. Facing the chilling reality of Ivan's military interrogation, Eugene abandons his delusions of generic protagonist supremacy and serves as Ivan's reluctant insider asset to identify and decode other transmigrators. Powers: Unique Transmigrator System interface granting quest-based stat progression, status window assessment, inventory storage, and systemic combat skill compensation.

A horned demon centurion sworn to the Imperial Guard of the Sixth Dragon General, Aiphelos represents the disciplined, unyielding remnants of the Demonic Army. Tasked with orchestrating the derailment and slaughter of Saint Yansk's incoming student convoy, his mission was engineered as a declaration of renewed war. Stripped of his pride, defeated by Ivan's asymmetric firearms combat, and denied a warrior's death, Aiphelos is systematically broken, stripped of his previous demonic identity, and repurposed as an indentured laborer at Ivan's orphanage. Powers: High-density demonic carnal mana, reinforced demonic horn/hide durability, heavy broadsword mastery, and command authority over demonic raiding squads.

A forty-year-old veteran Huscarl warrior and covert operative hailing from the martial northern realm of Droan. Tasked with deep-cover intelligence gathering inside the Tsardom of Krasilov, Mord masquerades as an oversized freshman within Saint Yansk University's physical education department. His mission to scout weaknesses in Krasilov's upcoming generation collides directly with Ivan during combat evaluations, leading to an immediate tactical dismantling of his cover. Powers: Droan Huscarl berserker conditioning, heavy armor combat specialization, high physical impact resistance, and foreign military espionage tradecraft.