Two sources (Thomas Keightley's _World Guide to Gnomes_, et al, & the Funk & Wagnall's Standard Dictionary of Folklore, etc.) inform me that the "vila" (pl. vile) is, indeed a Slavic nymph of the woods, fields, streams, & lakes, "the spirits of virgins & children, who leave their graves to dance at night." While "hostile to men," they do help the occasional hero. (This is why I so enjoy the vile in the 4th Harry Potter book, who are apparently irresistible to men, but who also display a less sedate side.)
First time I came across this meaning was as Villa (pronounced Vilya) from "The Merry Widow", where there's an aria telling the story. The sight of a villa can enchant a man, but if she kisses him, he'll die. Hardly seems fitting for our Fearful Hero, does it?