Sif

Personality and Function
Sif is an UNSC A.I. on the Tiara Space Station, in orbit above Harvest. Near the center of the Tiara was a room which housed her data center that contained the peocessor clusters and storage arrays that served her core logic.

Her chosen avatar takes the form of a woman with an ankle-length sleeveless gown and long golden hair; she also gives the appearance of Nordic royalty. She choose this avatar because many of Harvest's settlers where from Earth's old heartland, which could trace their ancestry back to Scandinavia.

She is in charge of Harvest's shipping operations which included the balancing of the Tiara, the transporting of human and shipping traffic up and down the space elevator, and control of the passenger and cargo transport in and out of the Tiara. Mack talks with Sif often, albeit oftentimes to her annoyance and frustration although deep down Sif loves Mack.

Right before the tiara is destroyed, Sif, after being destroyed by Loki was revived by the Huragok Lighter Then Some, she went rampant. She died right after she told Mack that she loved him, it is unknown if her message got through to him though.

Trivia

 * Sif is the wife of Thor in Norse mythology.