More to the point,and I blame the fact I've been watching too much underworld lately
A vampire stashed away on a mountain-side somewhere,a rich fancy castle-like place(now for those who've seen underworld should already know where I'm going with this).
You help him,you get the poryphic hemophilia(spell check please)...
Now for where the wolves come in...
They're pissed and tired of being slaves so they're going to revolt pretty simple like that..
You get to become a werewolf going that route
both opportunities would be there and of course choice effects which curse you get,so there becomes no worries on getting both and glitching the game with some were-pire hybrid thing.
So any better ideas feel free to throw them out there and my apologies if something similiar has been posted previously.