OVA
Description
Cyborg 0018, also known as Set or Seth, is a character created for the crossover OVA Cyborg 009 vs. Devilman. He is designated as the final member of the High-Teen Number cyborgs, a group developed by the scientist Dr. Adams. Set is the younger fraternal twin brother of Eva Maria Pallares, who is known as Cyborg 0015. His designation and his name, which in the biblical tradition is the third son of Adam and Eve born after the murder of Abel, carry thematic weight within the story. Set was born in a secret Black Ghost facility in Canada, where he was specifically developed to be part of an esper or mutant lineage. The process, however, left him in a sickly state, and he ultimately fell into a deep coma.

Physically, Set is a slender young man with incredibly fair skin, short pale silver hair with an asymmetrical fringe that falls over his right eye, and pale blue eyes. For most of the OVA, he is not seen in the High-Teen uniform because he is kept suspended and unconscious in a containment tube, often depicted as being naked. Beneath his synthetic skin lies a mechanical skeleton with wires, his brain being the only significant organic component left after his cybernetic conversion. The little that is shown of his original personality suggests he was a gentle and soft-spoken individual, who was deeply fond of his older sister and often relied on her.

Set's role in the story is that of a tragic catalyst and the ultimate obstacle. His comatose state is exploited by Dr. Adams for the Cyber Daemon project, a secret experiment to fuse a powerful cyborg host with a demon. Believing this process would cure her brother, Eva willingly cooperated with Dr. Adams, even going so far as to help abduct the character Miki Makimura to lure the demon-merged hero Akira Fudo, also known as Devilman, to the Black Ghost base. The plan succeeds, and Set is fused with the demon Atun. However, the result is not the cure Eva had hoped for. Upon awakening, the fusion is overtaken by the malevolent influence of Atun. In this new state, Set callously kills Dr. Adams by telekinetically snapping his neck, viewing his creator as having no further use. He then turns on his sister and attacks her without hesitation.

The relationship between Set and his sister Eva is the emotional core of his character. Before his transformation, he was dependent on her, and her primary motivation throughout the story is her desperate love for him and her desire to save him. After the merger with Atun, this bond is tragically inverted. The homicidal being that emerges is not only willing to kill anyone in his path, including his fellow High-Teen cyborgs, but also becomes specifically murderous towards Eva, showing no qualms about injuring her to gain the upper hand. This forces Eva into a direct confrontation with the brother she tried to rescue.

In terms of development, Set's arc is a short but complete transformation from a passive victim to a monstrous antagonist. He is first a comatose, sickly figure, then a mindless receptacle for a demon, and finally a powerful but corrupted fusion. In the climax of the OVA, after Eva initiates a process that shuts down the High-Teen Numbers self-repair functions, Set and the demon Atun undergo a further transformation into a gestalt being named Azazel. This form is incredibly powerful, slaughtering his former teammates with ease. Ultimately, Eva uses a last-ditch astral projection technique, with help from Cyborg 001, to reach out to her brother's lingering consciousness within Azazel. Her soul succeeds in separating Set from Atun, with Atun taking over Set's physical body while Set's soul finally passes away, shortly followed by Eva.

Set possesses notable abilities that are a combination of his inherent nature as an intentional mutant and his High-Teen cybernetic enhancements. He has powerful esper abilities similar to his sister, including telepathy, telekinesis, and the ability to project telekinetic shockwaves. As a High-Teen cyborg, Cyborg 0018 is outfitted with an accelerator, which allows him to move at incredible mach speeds, as well as a self-repair unit that restores his systems, recovers him from injuries, and grants him nearly unlimited stamina for his accelerator. After the merger with the demon Atun, his powers are greatly enhanced to a superhuman degree. His psychic abilities gain a disruptive function that can interfere with other psychics, even his sister. He becomes more muscular, gains red bolt-like tattoos on his face, and his lower body transforms to take on demonic features. As Azazel, his power is so immense that he is able to easily defeat multiple High-Teen cyborgs simultaneously and fight on par with Devilman and Cyborg 009.