Keith Anyan emerges not from birth but from artificial creation, gestated fourteen years within a test tube before entering the education system devoid of memories or an adulthood examination. His emotionless demeanor and exceptional abilities earn him the "android" label from peers. He ascends swiftly through military ranks, achieving supreme command over humanity by age thirty. His existence and grooming are meticulously orchestrated by Grandmother, the governing computer system engineered to eradicate the Mu psychic mutants and enforce absolute control over human society.

Presented initially as the model soldier, Keith operates with cold logic and unwavering system loyalty. Yet, interactions with specific individuals fracture this facade, revealing internal conflict and suppressed humanity. He forms a significant bond with classmate Sam Houston, who offers him kindness; following Sam's mental deterioration and death, Keith carries vials of Sam's blood as mementos. His path further intertwines with two Mu infiltrators: Seki Ray Shiroe, a rebellious student uncovering Keith's artificial origins, and Jonah Matsuka, a Mu posing as a human who becomes Keith's devoted servant, using psychic powers to protect him. Matsuka's death shielding Keith from assassination leaves a profound impact.

Keith transcends the role of simple antagonist. He demonstrates awareness of the system's flaws, occasionally questioning Grandmother's directives even while enforcing its brutal policies against the Mu. He deliberately shields Shiroe and Matsuka's Mu identities from detection, suggesting capacity for discretion and perhaps empathy. His distrust of the Mu stems from their perceived threat to order, yet his experiences with them complicate his worldview. A pivotal shift occurs when Grandmother directly manipulates his mind, revealing itself as merely a subsidiary of the deeper control system, Computer Terra. This act shatters Keith's allegiance.

In his final act, Keith executes a calculated betrayal, destroying Computer Terra to dismantle humanity's oppressive control structure. This action facilitates the Mu's return to Terra at the cost of his own life. His final command to loyal subordinate Serge Sturgeon is to ensure human-Mu cooperation for a better future. An epilogue depicts a future where Keith is reincarnated, reunited with Jomy Marcus Shin on a restored Earth, symbolizing conflict resolution. Across adaptations, Keith remains defined by his profound isolation, intellectual brilliance, the internal struggle between programmed duty and burgeoning individuality, and his ultimate rejection of the system that created him.