Serina

Serina was an artificial intelligence (AI) construct that was assigned to the, a modified Phoenix-class Colony Ship.

Overview
Little is known about Serina at this point other than the fact that she acts as a Military Advisory AI, which may, or may not be, her only function. She is a smart AI (see quotes beneath), which is usually a sign of advanced memory capacity, like Cortana. In contrast, other AI's known throughout the Halo Canon exhibit only minor aspects of personality. Her avatar is a young female with long hair. Her clothes look like a lab coat.

As the Spirit of Fire was too far away from UNSC territory and travelling without an FTL drive, it is unlikely that Serina was deleted.

Quotes

 * "Recalling surface squads so we can all die together. Aye sir!"
 * "Well, this is new... and scary." (Upon seeing the Flood)
 * "The MAC is online and primed. Payback time!"
 * "Expecting trouble, Captain?"
 * "Standard orbit achieved, all status systems normal."
 * "So... nothing too difficult then?"
 * "Here are some reinforcements... play nice."
 * "So, we left a note saying we're leaving, right?"
 * "Well, it'll be pretty obvious if he succeeds."
 * "Aye sir, crazy mystery trip to Arcadia plotted in, spinning up FTL drives."
 * "Threading a needle while accelerating around an exploding star inside a planet that's falling apart? Sure, why not?"
 * "So...am I the only one freaked out by the fact that we're inside the planet?"

Trivia

 * She is the first AI pictured in a game to wear clothes all over her body.
 * "Spinning up FTL drive" is a reference to Battlestar: Galactica, which uses this phrase constantly when the Fleet enters Lightspeed.
 * As said in the Halo Wars Manual, Serina seems to have a strange curiosity about chocolate.
 * Serina, knowing the crew of the Spirit of Fire may be on a one-way trip, manufactured and delivered fake emails from family members to the crew celebrating Valentine's day. No one ever suspected her of this deception.
 * She has a very sarcastic and detached nature, so detached in fact that she even seems to disregard the lives of others (such as when the Flood infect Marines) and even her own ship's crew, (such as when the Spirit of Fire is slowly being pulled inside the shield world) almost always responding with some curious or even dark joke.