Good and evil and what makes a monster all seem to be popular topics as of late. Really, this City is a breeding ground for moral ambiguity, so it doesn't surprise me in the least.
Being associated with an organization that is built on battling "evil" has given me good reason to think on definitions. Perhaps distinctions between good and bad weren't all that clear until Transylvania, but it is something that I've considered extensively.
To begin with, "monster" has nothing at all to do with species. Monstrousness manifests itself in behavior and actions; a human can be a monster just as easily as a vampire. A monster is characterized by evil actions.
"Evil" is more difficult. A werewolf might commit evil acts in his or her wolf form (then they might qualify as a monster), but as a human, they aren't evil by virtue of the wolf's actions. Simply killing isn't evil. An animal that kills to survive is not evil. For true evil to be present, a creature must be sentient and capable of acknowledging the consequences of its crimes.
Monsters are evil because they do evil deeds with full knowledge of the wrongness of their acts. A vampire who drinks blood is not a monster; drinking blood to survive isn't evil. To be entirely honest, I don't believe the occasional kill makes a vampire a monster, either. I'm aware that many vampires view humans as cattle. These vampires don't kill out of any sort of maliciousness.
What makes a monster is knowledge, evil action, and evil intent. A creature that is self-aware, murderous, and lacks regret is a monster. Enjoying the screams and fear of victims makes a monster. Taking lives primarily for the excitement it brings makes a monster.
As for the argument that Dracula's brides frequently bring up--no, your children were not themselves evil. Newborn vampires are barely aware; they're more animal than human, and feed and kill largely out of instinct. Yes, Van Helsing killed these newborn vampires. No, van Helsing isn't evil. He didn't destroy your children for the sake of his own enjoyment. They were killed to keep the world safe and uneaten--to keep them from growing into monsters like their mothers.
Yes, I've killed vampires myself. Hundreds, if the incident at the ball counts. My inventions have been responsible for untold deaths of all manner of creatures--vampires, werewolves, gargoyles, humans, anything the Order deems evil (although their idea of evil differs considerably, and I won't say that all of the deaths my inventions have caused were just). I was indirectly responsible for killing Verona. Would I consider myself a monster? No. I regret the loss of life that the Order's battle against evil causes. I wonder who the werewolf was before he was bitten, or how the vampire behaved before she was turned.
Do any of the other creatures who kill do that? I have no doubt. Some of us kill out of necessity. Not to eat, but to live--to protect ourselves and our families. We don't, however, enjoy it.
Likely, none of that made sense. My mind's entirely turned about from the circular reasoning certain monsters employ.
Addendum
Ah.
Here's the bit of cake I was able to scrape off of the walls...