Demon of the Dark Ones

From Author Wars - https://authorwars.com/publications/demon-of-the-dark-ones-9844.html

Overview:

Title: Demon of the Dark Ones
Author: Robert E. Vardeman, Victor Milán
Year: 1986
ISBN-10: 0441143148
Publisher: Ace Books
Price: $2.95
Pages: 221
Binding: Paperback
Type: Novel
Title Reference: Demon of the Dark Ones
Notes: Assumed 1st printing. Price in Canada C$3.75
Cover artist credit on this book from The Whole Science Fiction Data Base 6.