Azur is the second prince of the Kingdom of Fortna, a position that carries a profound and painful secret. In reality, he is not the true prince by birth. The original Azure Seth Fortna died in a violent accident at the age of four, killed by his own father. To conceal this tragedy and maintain the royal line, a young boy with a striking resemblance to the deceased prince was brought in to serve as a stand-in. Raised under the strict mandate to live and serve the kingdom without ever desiring or wanting anything for himself, this substitute grew up to become the elegant, intelligent, and deeply melancholic young man known as Prince Azure.

Physically, Azur is depicted as a tall and elegant figure with a strong, graceful build and aristocratic bearing. He has long black hair that is neatly styled into a braid, and his most notable feature is his sharp, golden-amber eyes, which some characters note bear a resemblance to the Grand Emperor's. His mannerisms are formal and self-controlled, befitting a prince who has been meticulously trained for his role.

Beneath this majestic exterior, Azur's personality is defined by a core of unhappiness and a sense of living a fake life. From childhood, he displayed a fascination with foreign lands and a deep craving for knowledge, collecting books and artifacts as a way to vicariously travel, which was ultimately a search for his own place in the world. Having never been allowed to wish for anything personal, he flawlessly performed his duties for the prosperity of the kingdom without any desire for the throne or personal gain. This detached worldview led him to initially regard Nina, a street orphan with rare blue eyes recruited to impersonate the late Princess Alisha, as nothing more than a disposable political pawn. His initial plan was to use her as a tool, intending to have her killed to provide a casus belli against the neighboring kingdom of Galgada.

However, his relationship with Nina becomes the catalyst for his most significant personal development. As he tutors her in the ways of a princess, he finds himself drawn to her authenticity and spirit. A pivotal moment occurs when Nina looks at him not as a prince, but as a person, which awakens in him long-suppressed emotions. He falls in love with her, revealing a more sensitive, caring, and gentle side of his nature. For the first time, he allows himself to wish for something: for Nina to stay and live with him in Fortna. This burgeoning love forces him to act against his programmed passivity, and he works tirelessly to nullify the political engagement that would send Nina away. When Nina ultimately chooses to leave for Galgada, believing it is the only way to protect him, Azur is deeply affected and agrees to take the throne from his father, the king, with a new, driving purpose: to bring Nina back home.

Azur is highly skilled and intelligent, possessing the wisdom to lead a regiment by the age of seventeen. He is a capable strategist and swordsman, and his upbringing under the Grand Emperor gave him a broad education in governance and statecraft. His key relationships include his servant Dytus, who has helped him maintain the princely facade since childhood, and the Grand Emperor, who personally taught him for years and for whom he feels great respect. His relationship with his younger half-brother, the true heir Muhulum, is also significant, as Muhulum's birth contributed to Azur's loss of purpose before Nina's arrival. His role in the story evolves from that of a cold, manipulative prince executing a political scheme to a lovesick and determined young king who is finally fighting for his own desires, even as he faces the fallout of his initial deception and the return of the real Princess Alisha.