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.
Coriolanus Snow. He was utterly disgusted when it was suggested that Lucy Gray and Tigris turned to prostitution because of poverty, and then he decided to utilise it and force the victors of the Hunger Games into sexual slavery. I know people complain about the Ballad of Songbirds and Snakes humanising him, but everything in that book just makes him a hundred times more fucked up as a villain.