In the manga Blame!, Cibo is a central figure whose history is deeply tied to the megastructure's central mystery. Originally, she served as the head scientist for the Bio-Electric Corporation, a powerful organization within the City. Her primary research involved a forbidden goal: creating an artificial Net Terminal Gene, the key needed to legitimately access the Netsphere, the City's control network. Her experiments ultimately failed, causing a catastrophic event that summoned the Safeguard, the system's violent security force. This led to the destruction of her entire laboratory and her subsequent imprisonment by the Corporation's President deep within its lowest levels.

When first encountered by the protagonist Killy, Cibo exists in a state of extreme decay, reduced to a barely living upper torso kept functional by integrated machinery. Despite her dire condition, her personality is characterized by a powerful and persistent scientific curiosity, particularly an obsessive interest in the Netsphere. She is perceptive, resourceful, and demonstrates a strong will to survive, which she channels into a pragmatic partnership with Killy. Recognizing his Gravitational Beam Emitter as the only means to navigate the City's Megastructure, she convinces him of her value as a hacker who can access needed genetic records, securing her escape and making herself an indispensable ally. Her actions are primarily driven by this unquenchable thirst for knowledge and a determination to atone for or resolve the consequences of her past experiments.

Cibo’s role in the story is that of Killy’s primary companion and foil. While Killy is a silent and almost inhumanly patient seeker, Cibo provides exposition, analysis, and a more emotionally reactive perspective for the reader. She is crucial for translating the world's complex technology and often formulates the plans that drive their shared journey. Her most significant relationship is with Killy, forming a symbiotic bond based on mutual necessity that evolves into a deep, if understated, loyalty. Equally important is her fraught relationship with Sanakan, a high-level Safeguard agent. Later in the narrative, after Cibo’s body is destroyed, she seizes control of Sanakan’s far more powerful form, leading to a tense coexistence where both consciousnesses battle for dominance within a single body.

Cibo’s development is uniquely physical and philosophical, as her consciousness is entirely digitized and separable from her form. Over the course of the manga, she inhabits several distinct bodies: her original, imprisoned decaying form; a new, functional body she constructs for herself; the hijacked body of her enemy Sanakan; and even a version of her original body from an alternate reality. This constant state of transfer and transformation means her personal growth is often intertwined with the acquisition of new abilities and the loss of her previous physical selves. Notably, at the story's climax, she becomes the unintended carrier for the new Net Terminal Gene, which manifests as a child-like sphere within her. This transforms her from a seeker of the gene into its physical vessel, a role that ultimately leads to her final sacrifice to protect the future it represents.

In terms of abilities, Cibo is a prodigious scientist and a master hacker capable of interfacing directly with the City's complex systems to access information and manipulate technology. She can sense electromagnetic frequencies, read ancient scripts, and communicate with the City's Builder robots. Her most profound ability, however, is her capacity to transfer her digitized consciousness into different cybernetic bodies, allowing her to survive physical destruction. When she assumes control of Sanakan's body, she gains access to high-level Safeguard powers, including formidable strength, shape-shifting, and the ability to generate powerful energy weapons and butterfly-like wings.