Luis de Alarcon commands the navigation of the flying island of Isla, holding the rank of Admiral within its government. He oversees Isla's safe passage and strategic course during its expedition.

He shares a long-standing friendship and mutual respect with flight instructor Juan Rodrigo Bandereas, collaborating on missions like locating missing students. Luis acts as a mentor and foster father figure to Claire Cruz. He played a pivotal role in convincing her to accept the Governorship of Isla, leveraging his congressional influence and securing her enrollment in the Aerial Division in exchange. He actively protected her student status, intervening against Countess Ulshyrra's attempts to remove her.

His guidance provides Claire emotional stability and counsel as she navigates her dual responsibilities and identity. He demonstrates awareness of the political complexities surrounding her true identity as Nina Viento and its implications for Isla's mission. Following the conflict with the Sky Clan, Luis remains part of Isla's governing structure as Claire departs to fulfill a treaty obligation at the Holy Spring.

Luis possesses brown hair, green eyes, and facial hair. His naval background and rank suggest extensive prior military experience.