If I can take a moment to inform then:
About half of CV3 takes place outside the castle. As you make your way to the castle as Trevor, you can pick up Sypha, Alucard, and one other character that hasn't appeared in the show. And then you spend the latter half of the game fighting your way through the castle.
So really this covers closer to half the game than a single level.
It's technically both. He lost his original wife before becoming a vampire(and became a vampire to spite God and whatnot), but he met Alucard's mother long after.
I mean, he's like a thousand years old. He's had more than one love in that time.