That mask, with those spikes, and that big mallet! The acting in this important-to-the-point-of-being-a-milestone horror film does rather let us down, as does the overly sparse soundtrack. No ambient sound? You know that these things are post-synchronized anyway, but this soundtrack is so much of a problem that it compromises the film.
Still, there are some good B-movie things here. Barbara Steele is a really striking, wild-looking presence, and this male witch is actually a reasonably good actor. A really formidable presence, anyway. The witch/vampire story is quite effective, or quite effective enough.
More significant of course is the superb, absolutely A-grade design, and the A+ cinematography and visual direction. Mario Bava laboured in the parched economic and generic fields in which he laboured. That aside, that not mattering, he was some filmmaker!