Oculus is a major figure in the world of Death Parade, presented as the creator of the arbitration system through which human souls are judged after death. He holds the highest known position in the hierarchy of arbiters and supervisors, standing above figures such as the overseer Nona, and he is regarded as the being closest to God, though it is implied that he is not God himself and that he ranks second in line to that position. He oversees all floors of the afterlife facility and works to maintain the balance and integrity of the judgment process across every level.

In appearance, Oculus is a slender elderly man with a casual and unassuming look. He wears a simple outfit consisting of a collared shirt with violet stripes, violet shorts, and pale brown slippers. His irises are black with striking neon green, cat-like pupils, and he wears pince-nez glasses to aid his eyesight. His light pink hair, accented with yellow highlights, is styled to resemble an open lotus flower, while his goatee is shaped like a closed lotus bud, giving him a distinctive and symbolic appearance that reflects his elevated status within the afterlife.

At first glance, Oculus comes across as cheerful, wise, and eccentric, with a playful, almost grandfatherly manner. He spends much of his leisure time playing a game of galactic pool, particularly with Nona, and he shows visible reluctance at the idea of playing with anyone else. Beneath this lighthearted exterior, however, lies a far more rigid and philosophically detached worldview. Oculus holds a near-nihilistic perspective on life, death, and judgment, believing that empathy and the meaning of life are concepts relevant only to beings capable of dying. In his view, arbiters are excluded from truly understanding the human condition because they cannot experience mortality themselves. This belief drives his central motivation: the preservation of the arbitration system and its foundational rule that arbiters must not possess human emotions. He considers humans unfit to judge other humans because of the inherent subjectivity and emotional bias attached to mortality, and he enforces this principle strictly across the hierarchy. Though he rarely displays overt malice, he is deeply suspicious of any emotional development in arbiters, viewing it as a potential threat to the stability of the system he created. His calm and whimsical persona conceals an unwavering adherence to cold logic, which makes his authority feel unsettling.

In the story, Oculus serves as the foundational authority behind the afterlife's judgment structure. He does not frequently interfere with the day-to-day judgments carried out by arbiters such as Decim or by overseers such as Nona, but his occasional presence signals a looming authority that all other characters must respect. His role is largely that of a distant architect and observer, one who monitors the workings of the system rather than taking part in individual cases. He is especially drawn to the question of what happens when an arbiter begins to develop emotional understanding, and he keeps a watchful eye on developments that challenge the principles he established.

His key relationships reflect his position and philosophy. He often plays galactic pool with Nona and seems to enjoy her company, though he becomes wary of her when she challenges the status quo; their relationship fluctuates between that of an old mentor and an authoritative superior keeping a watchful eye over a potential source of disruption. His connection to Decim is more indirect, but it is significant. Oculus rarely interacts with Decim directly, yet Decim's growing emotional depth, encouraged in part by Nona's involvement, places him in philosophical opposition to everything Oculus believes. In this sense, Decim becomes the living test of whether Oculus's worldview is correct, and Oculus watches that development with suspicion and interest rather than approval.

In terms of development, Oculus remains a largely constant figure throughout the series. He does not undergo a personal transformation, and his convictions do not waver. Instead, he functions as a fixed point of authority against which the emotional growth of the arbiters is measured, and the narrative uses his rigidity to raise questions about whether a non-human being can truly understand human emotion and whether the judgment system he built is just. His presence represents the impersonal machinery of the afterlife, and his philosophy provides the central conflict for characters who begin to move beyond the emotionless role he has assigned them.

Oculus also possesses a unique ability tied to his design. He can extend the lotus-shaped goatee on his chin to read the memories of others, allowing him to peer into their past experiences and thoughts without requiring verbal confirmation or participation. This power grants him deep insight into individuals and makes him highly observant within his domain, reinforcing his role as a being who operates beyond the limits of ordinary arbiters. It serves as a tool of surveillance and oversight, and the lotus imagery throughout his appearance symbolizes knowledge, enlightenment, and hidden depth, aligning with his god-like role as the architect and guardian of the judgment system. His game of choice, galactic pool, further symbolizes his control over the many realms and characters within the system, as he manipulates the larger order from a position far above the individual souls who pass through it.