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.
At some point during the Spirit's drift, Serina deactivated herself per rampancy protocols. Thus the Spirit was left without an AI until the discovery of Isabel. Once Isabel was brought aboard, much of Serina's work continued to be used and was built upon by her.
She has a very sarcastic and detached nature. She frequently seems to disregard the lives of others, even her own ship's crew - such as when the Spirit of Fire is slowly being pulled inside the Shield World - almost always responding to their peril with some curious remark or dark joke.
Her avatar was a young female with long hair and a lab coat. She spoke with an English accent. Beneath all her sarcastic comments and seemingly uncaring attitude, she turned out to be kinder than she seems. Serina had an interest in human relationships and chocolate.