It’s my opinion that the scariest sort of villain is the kind that believes that what they’re doing is truly good. Hell, a quick Google search tells me that a lot of people have trouble deciding whether Umbridge is more evil than Voldemort himself. This sort of villain is even more frightening when they think they’re doing God’s work, because for them, that’s the ultimate justification for their actions. No human force is gonna convince someone who thinks they have divine purpose to stop what they’re doing. I’ve been rereading the Wheel of Time books all summer, and one of my least favorite groups of characters—moreso than even the Forsaken (the Dark One’s lieutenants) themselves—is the Children of the Light. The Whitecloaks, as they’re called by pretty much everyone who isn’t one, embrace a philosophy that’s basically ‘McCarthyism: The Fantasy Edition’. Whitecloaks believe they’re doing the Creator’s work by eliminating the world of dangerous Darkfriends, but their methods are more along the lines of ‘anyone who questions our methods or gets in our way or is nice to someone we don’t like must walk in the Shadow’. Whitecloak Questioners start from the unshakeable belief that you’re guilty, and are only trying to get a confession out of you.
Frollo from The Hunchback of Notre-Dame is a rare case where the ultra-religious villain is also the main bad guy. Frollo casually tortures, imprisons, and murders those he believes to be heretics; he was actually going to drop an infant down a well because its mother was a g*psy, and he engages in some of the most egregious and melodramatic slut-shaming and victim-blaming I’ve ever seen to make himself feel better about the fact that watching Esmeralda dance gave him a not-very-holy boner.
The problem with this sort of religious character is that there are only rarely positive portrayals of religious devotees to balance out the fanatical ones.
In the Wheel of Time series, pretty much no one likes the Children of the Light, but there’s no, like, sisterhood of devoutly religious women who embrace difference and encourage others to walk in the Light joyfully or anything. (No, the Aes Sedai don’t count—they’re not coded as religious in the way the Whitecloaks are.) Although the whole of the Wheel of Time universe believes in the same Creator vs. Dark One, Light and Shadow creation myth, most of the characters are at best what I’d call spiritual or non-denominational. They believe, of course, but they don’t follow any particular creed besides ‘the Light is good, the Dark One is bad’.
Hunchback is a notable exception, since we have the Archdeacon of Notre-Dame as a foil to Frollo. The Archdeacon behaves in a way that exemplifies what true Christian behavior is: he is accepting of and loving to all people, even those of different faiths or backgrounds; he encourages spiritual growth through challenging situations; and he sees the beauty and potential in everything and everyone. It’s a rare blessing to have a clear example of what a proper religious figure should look like as a counter to the fanaticism displayed by the villain.
I don’t have a problem necessarily with the idea of the ultra-religious fanatic as a villain archetype—it’s an interesting statement about the fact that rigidity and dogmatism can be destructive, and as I mentioned earlier, it’s much scarier when the villain believes he has the inarguable moral high ground. However, I do take umbrage—ha ha, see what I did there—when this character type is the only religious representation in a series. When there’s not something to counter it, it only serves to perpetuate the stereotype that all religious people are moral objectivists with a superiority complex.