Catherine spends more time with Vincent as their relationship develops, neglecting her duties as a succubus.
It's unclear if Catherine has a true interest in and feelings for Vincent, but given that she allows herself to be with him in certain endings and is upset when he attempts to leave her, it seems that a part of Catherine truly does love Vincent.
Catherine is prone to having rapid swings of emotions — she's revealed to be rather emotional, experiencing rage one moment and joy the next.
Catherine is more playful, unpredictable, mischievous, wild and naughty, a contrast to Katherine's serious attitude.While Katherine pushes marriage, Catherine thinks marriage is overrated and doesn't see it as more than a man-made tradition instead of something god-given.She wears a white corset-like shirt with a red ribbon tied into her bow, a white miniskirt, white stockings and white shoes.While at Vincent's apartment, she sometimes wears a t-shirt with four hearts, with 1.5 of the 4 filled and "empty" underneath. It is unclear if this shirt is Catherine's or Vincent's.Freedom defines her entire attitude and feelings towards life: she's impulsive and resists commitment.
This is demonstrated by the fact that she works with Dumuzid to corral men into the Nightmares "on a whim".She has a tendency to give violent love bites, which Vincent has to cover up with bandages to hide.In addition, due to her succubus nature, Catherine may be a rapist and Vincent could be viewed as a rape victim.Although many would call her "evil", her mission is to help clear the world and human gene pool of unfaithful cheating men.Those who succumb to her beauty die from a curse known as the "Woman's Wrath".Unlike Katherine, Catherine doesn't seem to mind Vincent's drinking and smoking habits.