[quote=@HaleyTheRandom]
Basically, the two species rip each other apart. I don't know how else to explain it xD.
[/quote]

Well, explain why and how exactly do they manage to rip each other apart when no one else in the world manages that? 
Also, what's with that strange opposition of vampires and werewolves? Is there a reason to them being deadly to each other?