Cyrus Kriticos was a ghost hunter who recreated Basileus's Machine and gathered the ghosts of The Black Zodiac, in an attempt to open and gain control over the Ocularis Infernum and become the most powerful man on Earth.
Cyrus' nephew, Arthur, described him as not being very popular with the family since he, apparently, squandered the Kriticos family fortune. He wasn't too close with his nephew and had only seen him seldomly as a child. At an unknown point, Cyrus and his secret lover, Kalina Oretzia, discovered The Arcanum and Cyrus 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.
During the capture of the twelfth ghost, in the ensuing chaos, Cyrus and Kalina killed Kalina's fellow spirit liberator, Damon, for the tape-recorded Latin chant (needed to force the captive ghosts to use their life force to power up the machine) and faked Cyrus's death via decapitation.
Cyrus pretends that his nephew, Arthur and his family have inherited his supposed mansion, so that Arthur will be forced to become the thirteenth ghost for his children's lives. While Kalina protects Arthur from the rampant ghosts (as the machine requires a ghost who commits suicide out of an act of pure love to represent The Broken Heart), Cyrus abducts Arthur's children, Bobby and Kathy, to force Arthur to become The Broken Heart for their lives.
Cyrus arrives at the machine's core, and orders Kalina to put Bobby and Kathy in jeopardy in order to force Arthur to become The Broken Heart, before playing Damon's tape-recorded spells throughout the house, which caused the twelve rampant ghosts to go to the core and power up the machine. He then activates a mechanism in cold blood which crushes Kalina between two glass walls (because she balked at his orders to put Bobby and Kathy in jeopardy), saying that greatness requires sacrifice.
When Arthur arrives at the core and notices from the twelve ghosts that Cyrus is actually alive and is not a ghost, the two have a vicious confrontation which ends when Maggie frees the ghosts from their trance. The furious ghosts then grab Cyrus and throw him into the core of the machine, slicing him to pieces.
- Cyrus's character is based off of Dr. Plato Zorba from the 1960 film, although his role (as the chief human antagonist who threatens the family's lives, and who even falsely poses as a ghost, and ultimately gets killed by the ghosts in the house) is also close to that of Benjamin Rush.
- Cyrus Kriticos' name derives from Cyrus Zorba, Plato's nephew in the 1960 film.
- Kalina once described Cyrus as having a nasty disposition of enslaving souls.
- Cyrus narrates the background files of each ghost.
- He viewed the Firstborn Son as a brat.
- He praised the killer of Susan for killing her, posthumously.
- His niece-in-law's death held just the proper magnitude of suffering that he required, making her his easiest choice.
- He couldn't say for sure if the Pilgrimess was a witch or not, implying that he was not sure.
- He considered Harold to be the strangest ghost he ever caught.
- His cane possesses a hidden knife inside it.
- He was the first to see the ghosts without the spectral viewers.
- The ghosts seen standing over Cyrus are the Pilgrimess, the Torn Prince, the Jackal, the Juggernaut, the Great Child and the Bound Woman. The Pilgrimess is replaced by the Hammer to toss him into the machine while the Angry Princess can be seen beyond the Great Child.
- It's unknown why Cyrus had hidden barrier spells installed into the mansion, but it could be speculated that these were to keep the ghosts from entering his hidden room with the Basileus Machine.