I was browsing vampire stuff here on the forums and it made me think of something I did with a dhampir a few months ago, so I thought I'd see what you all thought of it.
Basically the idea was that this 19 year old girl was attacked by a vampire that was a rival of her older brother who was made a vampire when she was 12 years old. Even though he was Lawful Evil, he still retained his love for his little sister.
While he managed to drive off the rival vampire, his little sister was too badly hurt to survive, and being a vampire fighter and not a cleric or something... he couldn't heal her... so he did the only thing he could. He made her a vampire.
Now, what happened next... neither of them is really sure... but she's not a vampire. She's a dhampir (with the fangs alternate ability... basically made her as much a vampire as possible, without actually being a vampire.) Maybe a cleric might be able to figure out why the vampirism only took partial hold, but she's not about to let them dissect her or anything to find out.
What do you guys think?
Perhaps the girl was a potential Sorcerer with the Celestial bloodline (and didn't know about it), but that effect got washed out when she got infected with vampirism? The holy component is gone, but it made her a half-vampire instead of a full one. Yeah, that's a really far-fetched idea but I got nothing else in mind.
I really like this as a race origin. Personally in my recent campaign setting i had them be the precursors to vampires instead of the other way around. Basically dhampirs were the descendants of the cult the created the first vampire, forever tainted by their ancestors heresy.