Blood Sabbath (1972) 
David, a Vietnam veteran, is walking through the woods one day when he is nearly knocked down by a hippie-bus, is sprayed with beer, and then shortly afterwards is accosted by lots of naked women who rob him. He awakes to find a beautiful water nymph tending over him. Smitten, David tries to learn all he can about this mysterious girl and in the process stumbles across a coven of witches, headed by Dyanne 'Ilsa' Thorne who inhabit the surrounding area, and whose main purpose in life concerns stealing children's souls and dancing around topless in black underwear all day long.
After learning that he and his mysterious nymph cannot be together in the mortal world due to him having a soul, David offers his soul as a trade for that of a child so that he and his water-dwelling fancy piece can be together forever.
At its core, Blood Sabbath is a tale of two beings attempting to overcome all obstacles to be together, this is however wrapped up in a dreamy, trippy, hippie ensemble of set pieces consisting mainly of lesbian witchcraft rituals and bongo music, with references to Vietnam peppered throughout. Truly one groovy little psychedelic head-trip of a film.
Originally posted here:
Nightmare USA Films Discussion Thread