Is vampirism a religion or a practise/way of life?
Vampirism is not a religion or a cult of any kind. There are Christian vampires, Buddhist vampires, Pagan vampires, and atheist vampires. But there is no “vampire” religion so-to-speak. And if anyone tells you there is, be careful that you know who you’re dealing with. As for being a way of life, I guess you could call it that. A vampire is either born a vampire, or turned by another vampire. Consequently, there are things vampires must do to in order to exist.