An F-rank hunter burdened with guilt after his younger brother Yoohyun dies protecting him in an S-rank dungeon. Using a Wishing Stone to regress five years, Yoojin dedicates his new life to keeping his brother safe while secretly operating as the "Perfect Caregiver." Prone to self-deprecating humor and reckless self-sacrifice, he uses emotional intelligence and psychological leverage to tame beasts and temper volatile S-ranks. Powers: Holds the Title Dragon Slayer and the L-rank skill Caregiver/Nurturer, which allows him to double the growth speed of targets, grant massive temporary stat buffs to Awakened individuals he has raised (matching his stats to theirs), and share sensory perception with tamed beasts. He also wields Teacher's Grace and resistance skills (Fear Resistance L-rank).

Yoojin’s younger brother and the leader of Haeyeon Guild. Awakening as an S-rank at an early age, he deliberately distanced himself from Yoojin in the original timeline to protect him from political targets, leading to painful misunderstandings. In the regressed timeline, he remains overprotective, possesses an aloof demeanor toward others, but softens exclusively around his older brother. Powers: S-rank fire-attribute elementalist wielding pitch-black flames (Ignition, Flame Ruler), enhanced agility, and specialized dual-blade/longsword combat arts capable of melting dungeon terrain.

A spirited teenage orphan exploited by abusive relatives until Yoojin steps in, guides her awakening, and becomes her legal guardian. Bright, sharp-tongued, and fiercely loyal, she treats Yoojin like a father and older brother, swiftly adjusting to the perils of the hunter world. Powers: S-rank water/ice-elemental combatant with skills like Cold Rain, Ice Castle, and Water Dragon Transformation, granting her vast area-of-effect crowd control, frozen barriers, and fluid mobility.

Initially an insecure F-rank hunter with severe trauma and low self-worth. Yoojin recognizes his hidden crafting aptitude and provides continuous emotional support and resources, helping him unlock a legendary production lineage. Powers: Title Master of the Forge / SS-rank skill Gold Workshop, allowing him to forge S-rank and higher weapons, repair mythical gear, and access a pocket-dimension smithy.

The leader of South Korea's number-one guild. Wealthy, bored, and ruthlessly intelligent, Hyunjae is fascinated by Yoojin's mysterious knowledge and unique ability to handle uncontrollable S-classes. He frequently acts as an ambiguous benefactor, contractor, and manipulative ally. Powers: S-rank electric-elemental warrior wielding chain weapons infused with golden lightning (Thunder Chains), granting immense destructive power, paralysis effects, and absolute spatial control.

An orphaned Horned Flame Lion cub rescued by Yoojin from a dangerous breeding operation. Thanks to Yoojin’s Nurturer skill, Peace develops an affectionate dog-like personality at home while maintaining ferocious predatory instincts in battle. Powers: Body-size manipulation (shrinking to puppy size or expanding to giant beast size), S-rank flame breath, high-speed leaping, and horned charge attacks.

A principled public servant and S-rank hunter tasked with containing collateral damage caused by hunters and guilds. Stoic, weary, and bound by duty, he views the unchecked power of S-ranks as a societal hazard, yet develops a quiet respect for Yoojin’s peace-keeping influence. Powers: S-rank physical combatant specialized in Nullification, impact absorption, and hyper-dense physical durability designed specifically to suppress rogue S-class hunters.

The boisterous, straightforward leader of the all-offensive Breaker Guild. Valuing physical strength, direct action, and camaraderie over backroom politics, she quickly forms an easygoing, protective bond with Yoojin. Powers: S-rank berserker wielding a giant polearm/halberd, enhanced by earth/force amplification skills and shockwave generation.

A timid hunter from overseas suffering under the tyrannical dominance of his sister Riette. Yoojin provides him psychological sanctuary, earning Noah's unwavering loyalty and submission. Powers: Unique transformation skills allowing him to shift into a winged dragon, offering high-speed flight, aerial combat superiority, and poison-resistant scales.