Khun Aguero Agnes is depicted with cobalt blue eyes—ultramarine in Part I and a deeper shade of cobalt in Part II. He has silver-blue hair, a common trait among members of the Khun Family, which falls to his shoulders. His bangs frame his forehead, occasionally tied back into a small ponytail.

Although smaller in build compared to many of his peers, Khun maintains a lean, muscular physique. His appearance is frequently described as attractive, with several characters remarking on his good looks; series creator SIU has also noted his handsomeness in official commentary. As a member of the Khun Family, his skin is unusually pale, carrying a faint bluish undertone characteristic of his lineage.

Khun Aguero Agnes is portrayed as a cool-headed and highly intelligent individual, often serving as the strategist within his group. He is known for his scheming nature and takes pride in the success of his plans, at times displaying a smug attitude when they unfold as intended. His tactical brilliance has impressed even Rankers, such as during the Hide-and-Seek game, where he was described as “a dangerous being.” Khun’s natural tendency is to manipulate circumstances and people to his advantage, guided by what he himself terms “the mindset of a ruler.” Unwilling to simply follow established rules, he often bends or rewrites them in pursuit of his own goals.

While usually composed and approachable, Khun can be ruthless when the situation demands it, showing little hesitation in using others if necessary. At the same time, he exhibits a playful side, taking amusement in manipulating scenarios and observing the results. This attitude partly stems from his upbringing in the Khun Family, where he was denied a normal childhood due to the constant political conflicts among his relatives. His boldness is further highlighted by actions such as stealing from Khun Eduan’s treasure chambers.

Beneath this exterior, Khun is a more sensitive and empathetic figure than he initially appears. SIU has described him as “more human” than many other characters in the series. He is especially cautious and protective regarding Baam, often taking responsibilities onto himself rather than entrusting them to others, which reflects his guarded personality. To those unfamiliar with him, Khun may seem cold, but his behavior is influenced by the emotional defenses he has built due to past experiences.

His early bond with his half-sibling Maria illustrates his longing for genuine connections. Drawn to her kindness in the midst of the Khun Family’s schemes, he experienced a sense of loss when she disappeared, leaving him without companionship or purpose. This emptiness partly explains his interest in Baam and Rachel, as he sought to rediscover friendship and passion through them. Rak Wraithraiser metaphorically described this void as Khun having “lost his banana.”

Despite his reserved nature, Khun treasures those he values and is willing to take risks or endure isolation to protect them. He once explained to Wangnan that if he found a precious jewel, he would hide it away from the world, even at the cost of never seeing it again. This philosophy underlies his loyalty to those he holds dear, whether striving to elevate Baam to the summit of the Tower or ensuring Maria found a place of safety, even if it meant losing her presence in his life.

Khun Aguero Agnes was born into the Khun Family as a son of Khun Eduan. His maternal lineage, however, was considered less distinguished, leaving the status of his descent somewhat ambiguous. He grew up alongside his older sister and his younger cousin, Kiseia.

At the age of ten, Aguero participated in the Khun Family’s annual “official fights,” brutal contests among children of the branch families. Emerging as one of the victors, he earned the right to bear the Khun Family crest, while the defeated were cast aside.

Aguero’s mother placed great expectations on him, hoping he would support his older sister’s bid to become a Princess of Zahard. During this period, he encountered Maria, his sister’s rival, whose kindness and altruism stood in stark contrast to the ruthless politics of the family. Believing she deserved the role, Aguero manipulated the selection in Maria’s favor. However, this decision resulted in his sister’s failure, leading to the expulsion of their entire branch from the Khun Family. Kiseia came to resent Aguero for his betrayal, while Aguero himself was left isolated after Maria’s ascension as a Princess. The sense of loss and emptiness that followed would later resurface when he witnessed Baam’s determination to climb the Tower with Rachel.

Before being chosen as a Regular, Aguero infiltrated Khun Eduan’s treasure chamber, stealing several rare items. Among these were the Manbarondenna, a magical cloning bag, a high-grade suspendium pulley, and an Armor Inventory. These items would later prove essential during his climb.

Khun Aguero Agnes is recognized for his intellect, tactical genius, and natural combat abilities. While his primary role is that of a Light Bearer, his skills extend into physical combat, strategy, and weapon mastery

Combat Ability
Though best known for his intellect, Khun possesses the natural physical strength typical of the Ten Great Families. He has demonstrated the ability to carry the weight of multiple people effortlessly with one hand and block direct blows from powerful compression weapons. His agility was also evident during the Crown Game, where he was able to outmaneuver opponents despite being encumbered by his bag. Although he rarely takes a direct offensive approach, Khun has shown a willingness to injure or kill when necessary, using intimidation and calculated aggression to unsettle enemies.

Light Bearer Skills
As a Light Bearer, Khun specializes in strategy and battlefield coordination. He has consistently manipulated both allies and opponents to shape the outcome of tests, earning praise even from Rankers. During the Hide-and-Seek Test, for example, he exploited Quant’s impulsive personality, turning the Ranker’s behavior against him while secretly orchestrating events to ensure that his chosen allies advanced. In later arcs, he demonstrated the ability to outwit high-level opponents, including Ha Jinsung, by leveraging their overconfidence. His precision in planning has led others to describe him as “a dangerous being.”

Spear Proficiency
By bloodline, Khun is also a natural Spear Bearer, though he deliberately chose the Light Bearer position, stating his preference for command. Despite leaving the weapon largely unpracticed, he later demonstrated his skill by successfully eliminating massive Crystal Shards during the 42nd Floor stage of the Hell Train. Evan Edrok observed that Khun’s technique revealed his heritage and that he could easily fulfill the role of Spear Bearer if he wished.

Leadership and Strategy
Khun’s sharp intellect is his most defining strength. He is capable of predicting and manipulating outcomes with remarkable accuracy, such as ensuring coin flips land as intended. His leadership is equally notable: by Part II, he had gained a reputation as a capable commander, amassing wealth and forming a team of elite Regulars. His careful balance of manipulation, loyalty to trusted allies, and precise planning make him one of the most formidable E-rank Regulars.

Potential
Khun’s exact combat ceiling remains ambiguous, but hints within the story suggest that he ranks among the strongest of his class. It is implied that he was responsible for wounding Chang Blarode, one of the Top 5 E-rank Regulars, with Chang himself admitting that he could not defeat Khun in a direct fight.

The name Khun (쿤) is the standard romanization of his family name, belonging to one of the Ten Great Families. Within the series, members of the Khun Family are often associated with traits such as intelligence, cunning, and pale blue-tinted features, all of which align with Aguero’s portrayal.

His given name, Aguero Agnes, has no explicit meaning within the narrative but appears to be derived from Western influences, consistent with SIU’s tendency to use European-sounding names for members of the Khun lineage. “Aguero” is commonly used as a Spanish surname, while “Agnes” is of Greek origin, meaning “pure” or “chaste.”

The multiple romanizations of his name, Kun Agero Agnis, Khun Aguero Agnes, or Khun Ahgehro Ageunis—reflect variations in transliteration from Korean into English.