"Fuck-that's a dick move, even for such a young vampire....ok, let me explain. Lukas is a werewolf. He's-pretty rare, actually, most of them have been hunted down by this point...but anyways-werewolves and vampires-they have a special bond. Almost like....pet and master. Werewolves instinctually want to serve and protect a vampire, and vampires in return instinctively want to do right by their werewolves. When a werewolf meets a vampire, they're sort of-captured by them. It's a bit like having a human in your thrall, but it's stronger. And the more time a werewolf spends with their vampire, the more attached to them they'll be. But an unclaimed werewolf can't survive on his own. Not when he's already been entranced by a vamp. If things keep up the way they are...within a year, Lukas will die."
There's more but that was a lot of info dump-