Gale, a Rox demon rooted in Chinese mythological concepts of the Black Dragon—reflected in his alternative Japanese names Hei Long or Kokuryuu—embodies this heritage in both conceptual design and cultural naming origins. He serves exclusively as the demonic partner and guide to Akira across the series, protecting him from hostile entities and providing strategic insight during their journeys.

In Dark Version, Gale intervenes to shield Akira and his friends after they inadvertently summon a hostile Gargoyle in the world of Rem. Following this rescue, he remains Akira's constant companion, with his physical form evolving through multiple states shaped by player choices. This evolution culminates in an affiliation with dark elemental powers, marking a pivotal development in his capabilities.

His role continues in Ice Book, where he arrives in his evolved Blazeron form to rescue Akira from an attack by the demon Penanggal. Antagonist Isaac forcibly strips Gale of these acquired powers, reverting him to his original Rox state. Despite this setback, he resumes duties as Akira's partner and advisor for the remainder of their mission.

During Messiah Riser, Gale and another demon partner, Rand, defend their respective Devil Children from assassins at the story's outset. Here, Gale actively engages in combat while Akira participates by riding on his back.

Gale also appears in Puzzle de Call!, a puzzle-solving spin-off. He and Rand enter a miniature world trapping their human partners, navigating it by solving puzzles and recruiting other demons to assist in the rescue effort.