This is basically a superior adaptation of the novel Dracula. (Yes I know the history of why that is.)
One reading of this is that it is about recovery from sexual abuse trauma and ptsd. Orlok is one hell of a groomer. Ellen literally ends the power of abuse by sacrificially bringing it into the sunlight. Lots of interesting Eastern Orthodox imagery and ideas. Willem Dafoe is having a blast playing the best version of Van Hellsing put to screen.