Kalina Oretzia was Cyrus Kriticos' secret lover and servant. She served as the secondary antagonist. She was killed by her lover for balking at his orders to put Bobby and Kathy in jeopardy in order to manipulate Arthur.
Kalina was a member of the Spirit Reclamation Business, and was engaged to fellow member Damon Quinteros, but was having an affair with Cyrus Kriticos. At an unknown point, Cyrus and Kalina discovered The Arcanum and created Basileus's Machine in the form of a mansion from the blueprints in the Arcanum.
With a team which included Dennis Rafkin, Cyrus captured twelve earth-bound souls and had them moved to the basement of the house to become twelve of the thirteen ghosts in The Black Zodiac. Meanwhile, Kalina remained a member of the Spirit Reclamation Business to try and get spells needed to activate the machine from Damon.
During the capture of the twelfth ghost, in the ensuing chaos, Cyrus and Kalina killed Damon for the tape-recorded Latin chant (needed to cause the captive ghosts to use their life force to power up the machine) and faked Cyrus's death via decapitation.
When Arthur, Cyrus's nephew, inherits the machine disguised as a mansion and moves in with his family, Kalina travels to there with the Arcanum, the stolen spells, explosives and quicksilver flares.
Kalina meets up with Arthur in the house in time to save his daughter, Kathy from The Jackal and escape with them, Dennis and Maggie to the protected library. There, as Dennis and Kalina argue over the situation, Kalina reveals to Arthur that the fourth ghost is his deceased wife, both devastating and infuriating the man. After explaining the function of the machine and the ghosts, Kalina tries to convince Arthur to become the thirteenth ghost, lying to him that the thirteenth ghost is a failsafe that will shut off the machine.
When Dennis half-convinces Arthur otherwise, Kalina and Maggie go to the core of the machine, where Kalina knocks Maggie out and reunites with Cyrus. When Kalina balks at Cyrus's orders to put Katy and Bobby in danger (so as to force Arthur to become the thirteenth ghost), Cyrus traps Kalina in a chamber which crushes her to death between two glass walls.