Thanks to random Google adventuring, I just discovered this Chill series, published by Pinnacle Books from 1978 through 1980, all by an author I was previously unfamiliar with named Jory Sherman. Seven volumes in all, beginning with Satan’s Seed.
Actually I am still pretty unfamiliar with him, although I've learned he's written about a gajillion Westerns over the decades. This psychic investigator stuff looks like sheer pulp fiction cashing in on the pseudoscientific tabloid trends of that wild n' wooly decade known as the 1970s.
The series title is the nickname of one Dr. Russell V. Chillders, the aforementioned "psychic investigator" (why do psychics need to "investigate" shit? Wouldn't they already know?) Cover art is by Paul Stinson, save for the first two titles above; their more mildly Gothic imagery done by Jack Thurston (for UK cover art and some plot synopses, go here). I can't get over that Cabbage Patch doll head at the bottom!
As you peruse the covers, note the wonderfully dated fashions, standard horror tropes, occult fads, and paperbacks that cost merely a buck seventy-five. The '70s indeed.