OVA
Description
Dr. Adams Teufel is a complex antagonist whose full name carries deliberate thematic weight, with his personal name evoking the biblical first man and his surname meaning devil in German. He is a scientist who once worked for the sinister organization Black Ghost, where he was a colleague of the benevolent Dr. Gilmore on the original 00 Cyborg prototype project. However, his tenure with the organization was cut short due to his radically unconventional and cruel ideas. He was dismissed from the main development team for proposing the creation of cyborgs that incorporated demonic or occult elements, a concept his superiors found too abnormal and costly. This rejection from the scientific establishment became a core driver for his actions.

The character is defined by his cold, ruthless, and unhinged dedication to his research. Like many Black Ghost scientists, he operates with a complete disregard for ethics, showing a willingness to perform gruesome experiments on young people in his obsessive quest for the perfect subject. A flashback reveals him laughing maniacally and showing no concern for a test subject who was killed during experiments to create intentional mutants. His mania is also on display in the present, as he revels in the successful fusion of a demon with a cyborg body. Despite this cruelty, his personality has a single contradictory note: his relationship with his son. After his son, Edward, was critically injured in a lab accident that also cost Dr. Adams his right eye, he transformed Edward into the cyborg designated 0014. This act suggests a twisted form of love, as he was willing to use any means necessary to extend his only child's life, even if it meant turning him into a weapon.

Dr. Adams's primary motivation is to prove that his unorthodox theories on enhancing the human body are not only valid but superior. He seeks vindication for his dismissal from the original 00 Cyborg project. His ultimate ambition is realized in his crowning theoretical achievement: the Cyborg Daemon, or Devil-Remodeled Human. This concept involved creating a host body durable enough to house a demon, resulting in an ultimate, nearly unstoppable destructive life-form. To this end, he made a pact with the demon Atun, offering a suitable host in exchange for the chance to demonstrate his work's power to the world.

In the narrative of the crossover, Dr. Adams is the architect of the primary conflict. Having been rejected and forced to work in secret, he is supported by a Black Ghost executive named Van Vogt, who authorizes him to develop a new line of combat cyborgs known as the High-Teen Numbers. This team includes his son Edward as the leader, 0014. Among these cyborgs are the siblings 0015 and 0018, who are specially-engineered test subjects with esper powers. Dr. Adams selected the comatose 0018, named Seth, as the ideal host for the demon Atun. He manipulates the sister, 0015, by convincing her that merging Atun with her brother would heal him from his coma, using her love for her sibling to further his own ends. He also orders her to kidnap Miki Makimura to serve as bait for the hero Devilman, a necessary component of his plan.

The scientist's key relationships are largely transactional or exploitative. His most significant bond is with his son, Edward, who serves as his loyal enforcer. While Edward genuinely loves his father and is the Dragon to his operation, Dr. Adams's own feelings are more ambiguous, rooted in preserving his son's life at any cost. His relationship with his former colleague, Dr. Gilmore, represents a professional rivalry and a desire for validation. His greatest and most fatal relationship is with the demon Atun. Believing he could control the demon long enough to prove his theories correct, Dr. Adams makes a deal with him, offering Seth's body for possession. This act serves as the culmination of his arrogance.

The doctor's development in the story is a classic trajectory of hubris leading to a swift and brutal downfall. After years of being dismissed and working in the shadows, he finally achieves his goal. Upon successfully merging 0018 and Atun, he unveils his true, malicious intent, revealing that he never cared for the well-being of his test subjects and always planned to turn 0018 into a full demon. However, his triumph is short-lived. In a direct example of a villain being destroyed by the very power he sought to control, the newly-merged Atun immediately rebels against his creator. Instead of serving as a demonstration of Dr. Adams's genius, the demon shows his contempt for the scientist who thought he could use him, violently snapping his neck. This death reveals his role as a pawn who was unaware of the true scale of the threat he was unleashing.

As for notable abilities, Dr. Adams is not a physical combatant but a scientific genius of the highest order. Before his work with Black Ghost, he was a renowned physicist and cell biologist. He was famous for his work in the field of substitute cells, which he used to induce mutations in test subjects, granting them special powers beyond what cybernetics alone could provide. His ultimate scientific ability was in the conceptualization and execution of the Cyborg Daemon project, using his expertise to merge a biological host with a demonic entity on a cellular level, creating a near-unstoppable fusion that is incredibly difficult to reverse.