This Darkness comes to you from the fine folks at Brain Damage Films, and if you've seen anything by them, you know what to expect. Ultra-low budget horror movies with a fair amount of gore, usually some vampires...and not a lot of real talent. They do seem to have fun, though, and stay within their limits (both budgetry and skill) so to a B-Movie fan it's hard to really dislike them.
Word of warning, it's always a good sign to be wary of any production where someone's wearing multiple hats. "Written & Directed" or "Produced and Directed"...guess it cluds the objectivity or something. But when *any* of the above is also an actor in the movie...especially the star...then you really need to watch out. In this case, the main protagonist, the writer, and the director are all the same person.
The basic plot is simple, a biologist/professor at a university has been working on a "Vampire Virus" that would grant effective immortality to someone infected. A real vampire shows up and wants him to infect a bride for him...someone to live forever with him. The professor pretends to play along, only to double cross the vampire.
The story itself is a bis disconnected. I get the feeling that the writer was writing linearly without thinking ahead to how it would all fit together. Why the vampire chose who he did for his bride is, I don't think, explained, other than to save money by having one character/actress around for more scenes and thus the character was used for that role. The dojo/martial arts stuff didn't really contribute and I guess the producers knew someone who would work for cheap and they thought it would add some action interest and padding. A few scenes seemed to be only there to up the gore quantity as they don't really fill a need in the story and actually add to the confusion of "what's going on?"
So, in a way it was some fun; it kept moving, although not really in any sensical or cohesive direction. If you like really, really low budget vampire movies, its not bad.