It depends on your definition of "excessive". There is gore, some of it over the top, but the low budget practical effects tend to mitigate it. One scene in Episode 5 uses real pig intestines.
Mostly of the "violent psychopath locked in an insane asylum" variety. There's also a character in a wheelchair who is treated poorly in-universe and who is written as something of a tasteless joke. Ditto for an intellectually disabled character.
A Hannibal Lecter-esque serial killer eats his victims. It's not shown onscreen, but he does bite a chunk of flesh out of another character's face in one scene.
A cult leader is shown preaching to his followers and sacrificing one of them. Characters occasionally mention God or gods. One character is a Buddhist.