Warning: This contain spoilers.

Good movie.
The first girl killed was so dumb that I think it has to be one of the stupidest thing ever done by someone running away from someone trying to kill them in a movie if not the stupidest (i mean seriously hiding in an abandoned water well??????????!!!!!!!!!!!). I jumped one time (cheap scare but it got me) and I was tensed at one point by the end when she is left alone in a house surrounded while their master is entering and help is coming. I also did not see the end coming (both the real killer + her really becoming evil at the moment of her 18th birthday). I wish there was more gore (thought it would be a movie like that since they gave the highest rating before it started - like usual these ratings are idiotic) especially at the end when the master of that cult gets what is coming to him, sure that dirtbag ended up being right but still the fact remains that he is scum.
The cinematography and music are average. The acting, directing, editing, special effects, makeup and script are good. The costumes and story are great. The sets are excellent.