There's always a book someplace with all the information in it. It's always some old book written by a monk that went crazy.
This same book, despite being very old and very rare, is always available in a nearby library.
And there's always somebody in the group who just happens to know how to read the Latin.
The fact that the old book is invariably in Latin is also a trope, in that the evil in question invariably needs to be viewed or dealt with from the perspective of Catholicism.
Now THAT'S a plot bunny...
The main character is a Skeptic who has Lost His Way, and meeting the Devil allows him to regain his faith, which is all the stronger. I have yet to see an exorcism movie that doesn't follow this exact plot.
Is that because all exorcism movies are derived from Blatty's The Exorcist? Or was there something even before that one?
Clichéd characters always bug me because it means the writer is either lazy, politically correct, or no real bright.
Variant: The person with the mental disorder/disability is secretly magic/the only one who can save them/gets to live.The person with a mental disorder or disability turns out to be the bad guy.
Variant: The person with the mental disorder/disability is secretly magic/the only one who can save them/gets to live.
I dunno if all exorcism movies are based on The Exorcist or not, but since there's an obligation to accept that A) demons exist in this universe, B) exorcism is a known way to fight them, and C) there's a precedent for how said exorcism must be performed, I'd say it's not necessarily Blatty's fault. Perhaps Catholic dogma in general? I dunno. But they are pretty homogenous.
On the subject of religious horror, I have a plot bunny incubating in my brain about the End of Days as told by the Satanists, and how glorious an occasion it would be for them.
I'm not sure how to work it just yet, but it's there cooking.
Do your research on Satanism and you might have something.
Variant: The person with the mental disorder/disability is secretly magic/the only one who can save them/gets to live.
I dunno if all exorcism movies are based on The Exorcist or not, but since there's an obligation to accept that A) demons exist in this universe, B) exorcism is a known way to fight them, and C) there's a precedent for how said exorcism must be performed, I'd say it's not necessarily Blatty's fault. Perhaps Catholic dogma in general? I dunno. But they are pretty homogenous.