You know, I'm honestly surprised that that this is the first time I've seen the whole "Villainess Vs Heroine" genre get the yuri treatment.
Not that I'm complaining, I already adore everything about this manga.
It doesn't seem like she's really a vampire, I think it's more like she has some deeply rooted trauma that makes her acts like this. In short -she's gone a bit crazy.
At this point he's been working on White Knight for months, I'm going to guess that since the future manga stopped showing up. He'll finally use the experience he's gathered to make White Knight truly "his version".
I fail to see why anyone would want the sperados for their future plans. They hatched scheme after scheme and failed miserably.
I can assume it's to be sacrificial pawns.