Spoiler for like, any book existing.
I think mine has to be the villain in Mirror Man. Idk, he wasn’t intimidating, he wasn’t interesting. He was meh.
Also the villains from The Chain. Dear God they weren’t sympathetic in the slightest. The book tries to act like they were atleast pitiful but FROM THEIR INCEPTION, they were just evil assholes who enjoyed causing pain. The book itself wasn’t all that great anyways.
The author of Styx. If you have not read it, don’t read it. Starts as a fairly simple Greek mythology story, then you get explicitly detailed scenes of the male protagonist getting gang raped over and over for hundreds of pages, not even the same dudes each time, and his father sends him to get tortured to for no apparent reason. I was not prepared and the author clearly has some issues. It’s a wild book.