Oz is a principal character from an underwater realm. This powerful merman wields considerable power and combat skill. His abilities prominently feature hydrokinesis, granting precise control over water for tactical advantage. Oz possesses strategic intelligence, often anticipating adversaries' moves to maintain the upper hand.

He carries an air of mystery and intensity, often appearing brooding or menacing. Yet, his interactions with the central mermaid Marin reveal layers of vulnerability and emotional complexity. Their relationship forms a significant narrative element, marked by protective instincts and internal conflict as Oz balances his affection for Marin with their shared dangers and responsibilities as merfolk.

Psychologically, Oz exhibits an introverted and analytical nature, processing information perceptively. This manifests as a preference for solitude, intellectual curiosity—particularly about marine biology and ocean depths—and a reliance on logic over emotion in decision-making. He struggles with emotional connection, sometimes seeming detached or aloof socially.

His narrative function centers on engagement with Marin and Taro within the core storyline, contributing to themes of mystical conflict and interpersonal bonds. Oz consistently serves a combat role against antagonistic forces, utilizing his hydrokinesis and tactical acumen. His guarded emotional core remains a defining feature, selectively tempered by deepening bonds with key characters.