This is a fairly trite story line, about the unkillable evil, the same old super evil that cannot be killed. The treatment of the topic here is fairly clever, however.
We get more than one main character. In essence, we get an impression that the writer was alluding to "Lifeforce" in many ways, with one man a hands on operator battling demons in his life, and the other man an official who comes in to clean up. However, these characters are much more credible and identifiable than the ones from "Lifeforce".
The minor characters are plentiful. Some are three dimensional, but there are many who seem to be mere plot devices. These are minimal, and come across more credible, since they are demographic enough. For instance, there is one old demon battler, and three vigilantes who do the doomed vigilantes in the woods theme (which has become popular the past 10 years, but not trite yet). These are a minority, even in the small town, as there are nearly a hundred who meet to discuss action. Therefore, they seem a little more credible as a demographic.
The logical course of action is well thought out by the writer. Much of this is cleverly done. Near the beginning, a rancher tells the lawman that his cattle have been mutilated in a very unexplainable way. We soon learn this is not an isolated case, and the writer shows us very much in a few scenes. Someone is actually learning how to write at Sci Fi.
One hero has a lot of credibility, but the story seems to want to make him a cigarette smoker very badly, even though he is physically fit, lean, and a writer. Most of us have never even met a man who smokes who is lean, physically fit, and creative, nor one who is a jogger or writer. Also, he begins the day by waking up and jogging. Any one who jogs knows that this is unrealistic. Any one who did this would pull a muscle almost every time, and lose out on weeks at a time. The military purposely has GIs warm up with calisthenics before their jog.
But these are nit picks. Obviously one of the sponsors is involved with tobacco, so we can overlook this if it isn't overdone, and if the story is well done. This one passes the test, although the ending is a bit trite and over the top for this otherwise well written piece.