Howling II: Your Sister Is a Werewolf

Howling II Your Sister Is a Werewolf original title Howling II Stirba Werewolf Bitch is a 1985 horror film directed by Philippe Mora, as a sequel to the 1981 film The Howling. The film stars horror film veteran Christopher Lee along with Reb Brown and Annie McEnroe as they try to defeat Sybil Dannings werewolf queen Stirba and stop werewolves plans to conquer the world. Although Gary Brandner, author of The Howling novels, cowrote the screenplay, the Howling II film is largely unrelated to his Howling II novel from 1979, though it does introduce Eastern European customs and Romani into its werewolf mythology like the book.

Arriving in the Balkans, Ben and company wander through an ethnic folk festival, unaware that Stirba is off in her nearby castle already plotting their downfall. Stirba seems to have witchcraft powers as well as being a werewolf, for she intones the Wiccan chant Eko Eko Azarak. Eventually, the adventurers battle with Stirba in an assault that involves disguised dwarves, mutilated priests, and supernatural parasites, before Stirba is destroyed by Stefan. Ben and Jenny return home, where they become a couple and are greeted by a trick or treater dressed as a werewolf.This film is the only Howling sequel that directly follows the original films events though presumably with parallelearth incongruities, and is also the only Howling film to feature the input of the original novelist, Gary Brandner. Brandner was critical of the original 1981 film which was only a loose adaptation of his 1977 novel, and some elements of this sequel may have been deliberately divergent from the previous film, though some such as this films retconning of the worldwide revelation of the existence of werewolves seem to be accidental. ........

Source: Wikipedia