Daughter of Acheron Parthenopaeus, Katra was kori (handmaiden) to both her mother Artemis and her grandmother Apollymi. Artemis released Katra from her service as handmaiden so that Apollymi could help Acheron. She served as bodyguard to Cassandra Peters for five years. She also worked with Eneas Kafieri in his search for Atlantis and later with his daughter Megeara. Raised on Olympus, Katra used to sneak into Athena's temple and play with the owls. She is known as the Abadonna.

"Agrotera" is also one of the Greek names for Artemis, meaning "strength" or "huntress." Katra is as quick and deadly with her body as she is with her wit. She lives to taunt any male she can find, especially Stryker. Katra's powers, derived from both the sun and the moon, are second only to Acheron. She was once forbidden to be near or touch her father, as he was blind to the fate those closest to him, but she was always his unknown protector. At sixteen, she became able to invoke Apollymi's powers as well.

She is also a "conduit," through which godlike powers can be transferred. On the downside, her healing powers only work on other people. She can feel emotions, but cannot trace their root. The longer she is away from either the sun or the moon, the weaker she becomes. She has a small sfora from her father with Acheron's DNA in it that she wears around her neck; it was this sfora that she used to help imprison the Dimme.

She has a bow-and-arrow tattoo just above her left hip and a tattoo of a sun on her stomach. Some say it's the mark of the Destroyer; others believe it's the mark of Apostolos. More than likely, it's both. Kat has incredible weaknesses for New York at Christmas, flannel pajamas, chocolate, and her husband, Sin. After Katra was bitten by a gallu, Acheron blood-bonded his daughter to Sin in order to save her. She must drink from him every so often to survive.