Devlon is based on the character of Michael Myers. Dr. Cardán is obsessed with stopping Devlon just like Dr. Loomis is obsessed with stopping Michael. Also the story takes place on the Halloween night.
The mansion where much of the plot of "Cementerio del terror" (Cemetery of Terror) takes place is located near a cemetery, just as is the mansion in the movie "Quella villa accanto al cimitero" (The House by the Cemetery).