I imagine that Balthazar is a middle-aged man, maimed in some way, who possesses, or is possessed by, an explosive temper. With this in mind, I was reminded of Dennis Hopper's portayal of the infamous Frank Booth in Lynch's film Blue Velvet. Talk about a memorable character! So, with this established, I now have a vague sense of what Balthazar looks like and how he acts. While I don't foresee this character engaging in any erotic oedipal sessions, I am relatively certain that Balthazar is psychotic, and prone to fits of anger.
I have also established that he is physically maimed in some way. I am thinking that he lost one of his hands in a fight. For some reason, I keep coming back to the notion that he enjoys employing exotic poisons, which, given his explosive anger, is somewhat at odds with my initial impression of this character. Balthazar seems like the type of guy who would prefer to handle a threat head-on, rather than resort to something as subtle as poison. Perhaps he's really a coward, and his irascible temper is a facade? Anyway, this is how my mind works when an interesting NPC comes to light.