Everything in the world is not as easily defined as "good" and "bad" although we might wish for it to be. Things are often very grey and most people will fall within that range but strive to be better versions of themselves. In reality, very few people are purely evil – usually just psychopaths. Instead of showing purely negative characters, it would be more believable to show characters with more meat, with a strong background story of their present nature. Like Saras, for ex: he's been through hell and back after witnessing his mother's suicide and for that reason, he takes longer to open up to people, he's a bit more reserved but also respects his values more than an average person would. If they can justify an evil character, I'm all for it but otherwise, I usually flip the channel when some "vamp" comes on plotting nonsense for no good reason other than just for being evil. Truthfully, there is a little bit of evil in all of us at sometime whether its greed, lies, betrayal or something else.