Frisian Terror

In the late 80s a Russian general orders a search party to find a skull with supernatural powers in the Dutch forests which belonged to a Frisian medieval King The skull is found and a famous archaeologist gets possessed by it and turns into the kings faithful prophet A couple of years later the prophet who is now leader of a bloodthirsty cult which includes his beautiful girlfriend and family kills and tortures in the name of the Almighty King Sigurd