Even though, objectively speaking, The Abominable Dr. Phibes isn't very good, it's always been a sentimental favorite of mine. It helps that the movie is aware of its own absurdity—it actually chooses to revel in it rather than playing it straight—but the star of the film is its eccentric style, I'd say. Dr. Phibes—the designated genius-slash-madman of the story—lives in an art deco wonderland with a mechanical orchestra and a mute assistant with the gynecological-sounding name Vulnavia. In between playing his pipe organ (not a euphemism) and outfitting his home like a posh supper club, Phibes whiles away the hours plotting his revenge against the nine doctors who (he believes) are responsible for his wife's death on an operating table some years before. There's not much narrative tension, really, because we know that he will successfully kill eight of them—mimicking the plagues of Egypt in their deaths, however preposterously—which will bring us up to his climactic confrontation with the head doctor Vesalius. The joy in watching Dr. Phibes comes from Vincent Price's predictably hammy performance as the title character and the ridiculous set pieces that the film ticks through like clockwork.
It's extraordinary how Price manages to masticate the scenery so effectively when he has so few lines of dialogue in the film. You see, Phibes can't speak without the aid of a cord plugged into his neck that projects his voice through a phonograph horn—so when he does speak, it's usually in front of a portrait of his wife on his vanity... where he frequently says, 'Nine killed you! Nine shall die!' (This is in marked contrast to the much lesser sequel Dr. Phibes Rises Again, in which Phibes never shuts the fuck up. He's the chattiest cathy around in that movie.)
Yep, he's big on the theatrics, even when he doesn't have an audience for them. For example—for some reason, he has wax busts of all of his intended victims, and when he has successfully murdered one, he takes a blowtorch to the bust's face and melts it down. (Why? To what end?) We are told, as a matter of exposition, that Phibes was a religious scholar as well as a master organist—so this is intended to explain why he (poorly) recreated the plagues of Egypt in the murders. He even goes so far as to have metal medallions custom-made for each victim with the Hebrew symbol for the plagues embossed on them. (Again: why? We're verging on overkill here, Phibes. I guess that's why you're the madman.)
And poor Joseph Cotten... The star of such cinematic classics as Citizen Kane, The Third Man, and Shadow of a Doubt is reduced the thankless (and completely colorless) role of Vesalius, the head doctor and main target of Phibes. Here's what a dumbfuck Vesalius is. He knows (a) that he will likely be the ultimate victim of Phibes' revenge and (b) that Phibes is reenacting the plagues in order, but he fails predict that his son might be in danger in accordance with the ninth plague—the death of the first born. It's a good thing that the film is stylized in such a way that we don't expect basic cognitive skills from any of the characters. But again... poor, poor Joseph Cotten...