Originally an F-rank disposable foot soldier who perished during the apocalyptic collapse orchestrated by the Guardians, Hyunwook returns to his military past as a corporal armed with future knowledge and an insatiable appetite for metal. Pragmatic, calculating, and ruthless toward traitors, he operates on absolute strategic necessity, refusing to become a pawn to either corrupt military generals or divine entities. His evolution from an overlooked conscript to the master of the sky fortress Laputa is driven by an unyielding desire to prevent human extinction and personally execute his former executioner, Gordon Pracy. Combat abilities and traits: S-Rank combatant possessing the unique metabolic trait Biological Furnace, enabling the digestion of rare metals to perpetually augment physical stats and acquire innate weapon characteristics. Master of Metal Bending, Steel Rain (orbital-style kinetic bombardment), and Hellfire Mode. Wields the upgraded Dark Hand of the Cloud Master (evolved from the Cloud Blade), fragments of the demonic sword Moglay, the magic-nullifying Failnaught, and the sovereign manifestation of the Great Steel Emperor form.

The supreme commander of the divine faction known as the Guardians. Originally thought to be a transcendent entity orchestrating Earth's harvest from the shadows, he is revealed to be a fellow regressor who retains granular memory of failed timelines. Gordon views human casualties as acceptable collateral to engineer his specific vision of cosmic balance, maintaining an aura of calm, benevolent arrogance while orchestrating catastrophic timeline divergences. Combat abilities and traits: Transcendent-tier divine combatant with extensive mastery over reality-warping system authorities, ancient Titan control protocols, and high-order spatial manipulation. Capable of parrying S-rank strikes effortlessly and anticipating standard regressor strategies.

A military First Lieutenant and B-rank Paladin who initially approaches Hyunwook under orders of surveillance. Burdened by overbearing familial expectations and military bureaucracy, she finds purpose and genuine tactical agency alongside Hyunwook. Overcoming self-doubt, she sheds her administrative limitations to become the unbreakable vanguard of Steel Company, anchoring the frontline against cataclysmic incursions. Combat abilities and traits: Elite Paladin specializing in high-density defensive barriers, holy reinforcement, and frontline crowd control. Key technique includes Holy Bash, capable of fracturing high-tier exoskeletons and subduing biologically enhanced assassins.

An F-rank archer private originally destined to die anonymously during early gate incursions. Rescued and fostered by Hyunwook, Junmo develops intense loyalty toward his squad leader. During the brutal Cerberus incursion, he undergoes a trial by fire, shattering his psychological weakness and evolving into an indispensable aerial sniper and electromagnetic disruptor for the Steel Brigade. Combat abilities and traits: Awakened elemental sniper possessing Electric Manipulation, Self-Levitation, and multi-casting lightning trajectories. Equipped with the experimental Girin combat uniform, enabling high-speed aerial maneuverability and long-range armor-piercing kinetic lightning strikes.

A veteran military sergeant who conceals an assassination-focused skill tree behind her recognized role as a wind and spirit sorceress. Highly perceptive and emotionally detached, Sehee functions as the intelligence backbone and silent enforcer of Steel Company, neutralizing internal saboteurs and running covert shelter infiltrations without leaving a trace. Combat abilities and traits: Dual-specialist in spirit sorcery and lethal stealth assassination. Wields wind-based concealment veils, sensory disruption fields, high-velocity atmospheric blades, and close-quarters infiltration techniques.

An elite military sergeant and frontline swordsman haunted by the trauma of failing to protect civilians during early system outbreaks. Rebuilt through Hyunwook's uncompromising training and shared frontline combat, Youngjoon transforms his guilt into singular swordsmanship, serving as the primary physical offensive partner to Hyunwook against boss-level aberrations. Combat abilities and traits: Master swordsman specializing in high-speed linear acceleration and kinetic edge control. Capable of attuning to and wielding fragments of the demonic blade Moglay, executing devastating physical armor-shattering strikes.

The corrupt Conquest Team Leader of the Great Mountain Guild. Willing to sacrifice national defense and civilian safety for guild dominance and corporate kickbacks, he secretly collaborates with parasitic forces during the Great Seoul Wave, attempting to eliminate Hyunwook before being outmaneuvered and systematically destroyed. Combat abilities and traits: Advanced monster-taming sorcery, psychological mental-interference arts, and commanding authority over coordinated swarms of aberrant monsters.

The Saintess of the World Tree residing in the Republic of Chad. Her soul and biological lifespan are directly linked to the health of the sacred World Tree. Following Hyunwook's eradication of the parasitic Crimson Knight that poisoned her sanctuary, she forms a deep spiritual connection with him, humorously mistaking his cold tactical demands for a traditional marital commitment. Combat abilities and traits: Divine nature communion, high-tier purification magic, planetary mana restoration, and the ability to bestow ancient World Tree blessings capable of stabilizing biological mutations.

Known across South Korea as the "Fist King," Han Taesan is an S-rank powerhouse whose combat prowess is matched by his unyielding arrogance. Accustomed to unilateral dominance in hunter politics, he finds himself consistently outmaneuvered by Hyunwook during high-value gate operations. Combat abilities and traits: S-Rank physical brawler utilizing destructive shockwave generation, dense internal mana armor, and earth-shattering melee strikes.

The shrewd, razor-sharp Guild Master of Japan's Kurokami Guild. An opportunistic S-rank hunter who values practical survival and corporate power above national borders, Ren walks a razor's edge between being an adversary and an indispensable ally when regional disasters threaten total destruction. Combat abilities and traits: S-Rank swordsman possessing spatial-cleaving kenjutsu, shadow-stepping mobility, and acute combat perception capable of matching monstrous entities in single combat.

An unassuming Japanese F-rank hunter whose combat weakness belies an extraordinarily rare biological anomaly: she possesses the unique capability to bypass System translation filters and comprehend the native language of dimensional monsters. Rescued by Park Junmo, she becomes an indispensable guide through monster-held territories. Combat abilities and traits: Universal linguistic translation of dimensional entities, stealth evasion, and basic survival instincts.

A terrifying, brutal enforcer aligned with covert operational syndicates profiting from dimensional instability in Japan. Unforgiving, physically monstrous, and driven by raw violence, he acts as the physical hammer against any who threaten the instigation of the Night Parade. Combat abilities and traits: Monstrous physical strength, superhuman pain tolerance, and mastery over heavy blunt-force weaponry, primarily wielding a massive war hammer capable of shattering fortified bunkers.