Zero at the end SPOILERS
Why did Zero tell Yuki he would kill her in the future? Yes he is a hunter but I thought he had come to terms with the fact that there are both "good" and "bad" vampires. Why would he want to hunt vampires that aren't doing anything to harm anyone? Maybe vampire family's just living their daily life and minding their own business. It wasn't even the modern hunters policy to hunt vampires just because they were vampires.
"The ultimate acting is to destroy yourself."
- Klaus Kinski