The Expanse season 6 finale and strongly foreshadows her ominous future.
From season 3 to The Expanse season 6, Clarissa's redemption arc sees her progress from a vengeful murderer hellbent on killing James Holden for his role in her father Jules-Pierre Mao's imprisonment to a hopeful spirit trying to earn her keep on the Roci alongside the very people she tried to destroy. To aid her violent rampage, Clarissa had mods surgically implanted in her that provide bursts of extreme strength. The mods landed her in a high-security prison on Earth as seen in The Expanse season 5, before she escaped with Amos Burton in the aftermath of Marco Inaros' asteroid attack.
Although The Expanse had previously established the detriment of Clarissa Mao's implants through her fits of vomiting and unconsciousness upon each instance of activating them, the revelation of her illness comes as a surprise. In the books, Clarissa's declining health only explicitly surfaces in Persepolis Rising, which takes place 28 years after Babylon's Ashes — the novel on which season 6 is based. The early onset of her condition in The Expanse season 6 pits Clarissa on the brink of death when she struggles to fix the Roci's reactor in the heat of battle, in a moment that manifests the gravity of her predicament and her willingness to risk it all for her newfound family.
In Persepolis Rising, Clarissa's older age combined with the long-term effects of her mods have resulted in the deterioration of her body to the point where her impending death looms large in the series' seventh book. Introducing Clarissa’s ailment in The Expanse's final episode raises the stakes of the final battle against the Free Navy, as the moments of silence following her desperate scream over the ship's comms establish an air of suspense suggestive of Clarissa activating her mods to get the job done and sacrificing her life in the process. When Naomi eventually comes to her aid and finds her partially conscious after hitting her head, Clarissa tells her she didn't use her mods. Even though Clarissa doesn't end up losing her life for the sake of the Roci, the scenario illustrates her commitment to earning the trust of those around her in spite of the ever-present danger to her life.
The revelation of Clarissa's development of complex endocrine collapse syndrome strongly foreshadows the character's future should the remainder of The Expanse's source material see an on-screen adaptation one day. In that event, the question arises of whether the books' 28-year time jump would be shortened to accommodate Clarissa's failing health or if subsequent advances in medicine would have extended her life span. Either way, Clarissa still faces the task of breaking the news of her illness to her crewmates, indicating that The Expanse is far from finished with her.