Smashed heads! Smashed faces! A woman disemboweled and hanged with her own guts! Vaginal impalement with, er, a snap-together vagina impaler! Already a vocal cult calls the long-awaited, long-deferred final film in Dario Argento’s “Three Mothers” trilogy some kind of twisted Film Moe Dee classic—but for anyone with fond memories of Suspiria and Inferno three decades ago, it’s impossible to see this awe-inspiringly awful shocker as anything but a high-camp fiasco. A regrettably restrained Asia Argento plays the innocent who must confront the return of the all-powerful witch Mater Lachrymarum, the Mother of Tears, whose arrival triggers a cheapo apocalypse in modern-day Rome. Without Argento’s once-trademark cinematic panache, all that’s left is poorly staged, protracted sadism interrupted by expository narcolepsy, abysmal acting, and unintended horselaughs. Those who make a case for this as an elaborate jape get the most support from the movie’s deranged final third, which starts with a hilarious montage of cackling, clawing supermodel witches converging on Rome like a Transylvanian Sex and the City convention; it ends with Asia crawling through an excremental downpour toward a closing-shot curtain call, where she collapses in gales of cathartic laughter. If you believe someone of Dario Argento’s proven talent would make a movie so deliberately sucky, feel free to join in.