At least the Koontz books were well written, tho with some parts almost as outlandish as demons vs gargoyles. I agree with other posts this feels much like a ripoff of Underworld.
Extraordinary claims require extraordinary evidence - Carl Sagan
The same guy came up with the story for both this and Underworld... so... it's not a ripoff so much as a variation on a theme.
shareI just found on Netflix streaming yet another Frankenstein (2004) with Parker Posey that WAS based on DeanK's novels, or more properly this was from his screenplay and he wrote the series of novels afterward - and disavowed all credit for this 2004 made-for-TV movie. Sadly, what I thought was a fun set of novels by DeanK was made into a shlock-ish TV episode.
SO careful for what you wish for, Hollywood might do it.
Extraordinary claims require extraordinary evidence - Carl Sagan