Before she was Delphi, the AI was created under the name of Clearessa (AI Serial Number: CLR 8131-5), served as a battlefield intelligence assigned to Inner Colony battlegroups and Earth's Home Fleet. As Clearessa, the feminine AI struggled with an uncorrectable speech impediment that was only subverted by means of poetic rhyme and rudimentary text-to-speech software. While her ability to respond to others was greatly diminished, sometimes even requiring another AI to translate for her, Clearessa was recognized as an invaluable and skilled tactical mind by AI standards and was allowed to remain in active combat service based on an impressive combat record and support of the warship crews she served with. She was eventually assigned to the UNSC cruiser, Canberra under the command of Fleet Admiral Joseph Harper. During the Battle of Earth, the Canberra was gutted by Covenant plasma fire but the majority of the crew including Fleet Admiral Harper managed to escape to continue fighting. At the cost of her own sanity, she saved her crewmates and the remnants of her memory core were salvaged to create a new individual. This new AI, born on borrowed life, was Delphi - created a month before the Human-Covenant War's end. While Harper went on to retire from the UNSC Armed Forces, Delphi was reassigned to Rear Admiral Jazmine Utah as the admiral's logistical intelligence.
Under Utah's direction, Delph became a key asset of the Office of Naval Intelligence'sBeta-5 Division, a subdepartment established to handle ONI special warfare projects. Delphi's specific jurisdiction fell in with the secretive continuation of the SPARTAN-III Program, falling under the DELTA Initiative authority. This new generation of SPARTAN-IIIs was known as Delta Company, an organization that Delphi had a fondness for and a cause she believed in after learning of it from Rear Admiral Utah. Delphi would go on to play a key role in Delta Company's development, protecting the unit's secrecy from external intelligence threats, even other ONI departments, and helping manage the psychological and logistical functions of Delta Company with individuals like Dr. Reyna Zhou-Romero and Captain Andrew Johnson. When the UNSC finally discovered the DELTA Initiative's treachery following the unexpected consequences of Operation: DARK DESCENT, the DELTA Initiative was sacked and purged. Delphi was terminated upon discovering her early-stage of Rampancy, however, her neural network was retained based on the uniqueness of her history and her design capabilities in hopes that it might help with developing more advanced AI intelligences in the near future.
"Now, I want you to always remember. This is the greatest team you'll ever be a part of."
― Fleet Admiral Joseph Harper to a new crew aboard the UNSC Canberra.
The AI known as Clearessa entered service on the nineteenth of November 2551, still a year from the grievous Fall of Reach. Her brain-donor was an insignificant grandmother of an ONI officer who served with the Colonial Administrative Authority during the Insurrections. The grandmother's brain was acquired by the Office of Naval Intelligence following the woman's passing after a brief battle with an autoimmune disease. Assigned to the jurisdiction of ONI's LIBRARIAN Program, the brain would eventually be developed into the AI, Clearessa.
The LIBRARIAN Program was a classified project that sought to create Smart AI with the capacity to devour other AI in a timely and effective manner, thus, allowing an AI to assimilate rampant and less powerful AI constructs, allowing their data to be retained and used. This method was revolutionary in the aspect that it was hypothesized that it might be a method toward Smart AI escaping their technical restraints in their average seven-year-lifespans.