Given the context, it's a bit hard to tell. I'd say it's one of two things: sin (possibly lust in particular), or being a Grey Maiden.
Spoiler:
That phrase is actually spoken by the illusory Karzoug and was meant to be an evocative, if abstruse reference to some kind of underlying philosophy to which the Runelord of Lust might ascribe. My thought in designing the illusion was that it's of ancient creation and operates independently of the sinspawn sorcerer.
That makes more sense. Go with that.