I thought our new villain deserved his own thread!
I had been really looking forward to Culverton so had high expectations, but he was even better than I'd hoped. Although it's never said outright, he's clearly based on Jimmy Savile, and I imagine it was difficult to create a Jimmy Savile type character, without it being a Jimmy Savile impersonation. I thought Toby Smith made him his own, and was chillingly believable.
Serial killing is more acceptable TV than Jimmy Saville's crimes, and I wondered how on earth they would do that on a show which is not supposed to be extreme viewing. I thought it was very cleverly done, with all the little hints - Culverton sitting in the middle of a group of children, the mortuary being his favourite room and his inappropriateness with the body, keys to the hospital, secret passages, the suggestion to the girl when they're filming, the almost kiss with Sherlock. In the end, it wasn't actually the serial killing, per se, that made Culverton really, really creepy.
I liked that he was part of the establishment, like Magnussen, untouchable. And so chilling, because it's true.
Unlike Magnussen, he didn't have any special memory powers or talents that made him successful (apart from being a "personality" and managing to manipulate people). I thought it was an interesting contrast that Magnussen used his memory, whereas Culverton used a drug to erase memory in others.