Khun Aguero Agnis, a direct son of Khun Family head Eduan, bears his mother Agnis's surname signifying her lesser lineage within this Ten Great Family. His family faced expulsion and disgrace worse than death after his older sister failed to become a Zahard Princess, fueling his ambition to climb the Tower, gain power, and usurp his father's position. This event instilled a deep inferiority complex. Before entering the Tower, Khun displayed exceptional audacity by raiding Khun Eduan's treasure room, an unprecedented act. His harsh upbringing forced him into adult responsibilities early, depriving him of a typical childhood and creating a later ironic longing for simpler times. During his youth, he formed a significant bond with kind half-sibling Maria, a stark contrast to the family's cutthroat environment. He sacrificed their relationship to strategically help Maria become a Princess over his own sister. Her departure left him emotionally adrift, intensifying his distrust and desire for control. As a C-Rank Regular, he teams with Twenty-Fifth Bam and Rak Wraithraiser early in their ascent. Officially serving as a Light Bearer for its command role, he inherits ice-based Spear Bearer abilities from his father. His combat capabilities evolve significantly through acquiring the Enna Core lighthouse and ice-based Shinsu techniques, though he remains strategically focused on support and coordination over direct confrontation with powerful foes. Khun's personality blends cool-headed intellect with calculated ruthlessness. He consistently manipulates test rules and social dynamics, duplicating the Crown, bribing Anaak Jahad, and orchestrating Quant's defeat. Beneath this pragmatic exterior lies deep-seated sensitivity and loyalty. He harbors intense devotion to Bam, vowing to chase him anywhere and orchestrating elaborate protective schemes. Conversely, he nurtures a profound vendetta against Rachel for betraying Bam, manipulating teammates to feign friendship while secretly sabotaging her ambitions. Physically, he possesses angular cobalt-blue eyes and silvery-blue hair characteristic of the Khun lineage. His outfits vary: Part I includes a bandanna and formal wear; Part II shifts to practical safari gear; Part III introduces a small braid. He often wears earrings, potentially crafted from Suspendium. Throughout later arcs, his development intertwines with major events. During the Workshop Battle, he investigates rumors of Bam's survival, confirming his identity as Jyu Viole Grace and aiding his escape from FUG. His abilities undergo transformations like power awakenings and tactical innovations involving freezing techniques. Despite growth, he retains core traits—protecting cherished companions like jewels to be hidden and clinging to childlike pettiness in conflicts as compensation for his lost childhood.