Julius Ziltonia, second prince of the Kingdom of Ziltonia, possesses pronounced pride, frequent jealousy, and a selfish nature. His decisions profoundly impact others, especially Philia Adenauer, the Saint originally betrothed to him. Julius terminated their engagement, deeming Philia unappealing due to her extreme competence and perceived lack of emotional expressiveness. He then arranged her sale to the neighboring Kingdom of Parnacorta. This act stemmed partly from his desire to marry her younger sister, Mia Adenauer, and partly from resentment that Philia's capabilities overshadowed his position. A secret motive involved his father's improving health thanks to Philia's medicine; Julius wished for both his father and older brother to die, clearing his path to the throne.

Julius held a low opinion of competent women, viewing their abilities as threats to his perceived superiority. This misogynistic outlook fueled his hostility toward Philia, whose effectiveness in managing Ziltonia's defenses, healthcare, and administration inadvertently exposed his own inadequacies and laziness. Though regarded as a child prodigy in his youth, Julius failed to cultivate his talents, relying on past praise and royal status, resulting in significant incompetence in governance and crisis management.

Following Philia's removal, the Kingdom of Ziltonia declined rapidly. Critical systems she maintained collapsed, revealing Julius's inability to comprehend or manage her former responsibilities. He remained oblivious to her contributions and dismissed warnings about the kingdom's deterioration. His priorities shifted to self-aggrandizement, like commissioning gold statues, even as demonic incursions loomed. He refused Mia's urgent pleas to bolster defenses, ignoring Philia's direct warnings about the demonic threat.

Julius's interactions with Mia further illustrate his flaws. After manipulating events to become engaged to her, his cowardice emerged during a demon attack when he used her as a shield. This act, coupled with his consistent dismissal of her capabilities and concerns, solidified Mia's contempt and fueled her covert plans for revenge against him and their parents. Julius actively suppressed Philia's achievements within Ziltonia, burning copies of her book and intercepting her letter to Mia.

His role extends beyond personal failings to embodying the consequences of Ziltonia's corruption and ingratitude. The narrative positions him as a catalyst for the contrasting fates of Ziltonia and Parnacorta, highlighting the destructive impact of his entitlement and the systemic flaws within his kingdom.