*please excuse any spelling-errors. I wrote the below, on the fly.*
I was watching the unused Joker-scene, from "The Batman"-movie.
It's one piece of the teasers and trailers, that caught my eye, as a continuation of Hollywood's innacurate-portrayals, of mental-illness.
In the clip, the Joker is obviously a Sadist, but also an extreme-masochist, (a "pain-freak") as he is covered with healing-wounds, which are presented as being compulsively self-inflicted.
The Joker character is mutilating himself because he gets off on pain, even if it is his own.
Which, other than Albert Fish, is unheard of amongst Organized Psychopathic serial-killers. (Fish only managed to elude police as long as he did, because of the ineffective investigation-techniques of the early 20th-century).
That part bugged me because it's positioning an extremely-deviant-behavior in the place of an actually recognized mental-illness.
Typical "Hollywood-crazy" bullshit. It comes from writers being raised on TV-show/Movie-versions of insanity, but never actually having much (if any) actual contact with real-world people, displaying symptoms of a recognized form of Mental-illness.
A person that takes so much pleasure in pain, that they continuously rip their flesh, to get-off, would not be able to function in society, and would probably die young in a homeless-camp.
No way could they have the focus to pull off ingenious criminal-capers.
The closest I've ever seen ANY actor come to portraying a true-to-life mental-illness, in a Supervillain, was Frank Gorshin's portrayal of Riddler.
People focus on the goofy laugh, but pay attention to what he's doing in the clip below.
In my opinion, it is an excellent portrayal of a rapidly-cycling manic-depressive.
https://youtu.be/oJ-_sj9jUIM