I don't mind rough descriptions of brutal pain or practices that could be lethal if you imitated them in the real world, we have to be able to separate that. I don't think a story would be very readable or effective if it culminated in killing, if that were the high point of the story. I'd probably feel disgusted if I read a BDSM story set in a nazi death camp and ending in the victim being killed, because that blurs the limit between real and fantasy.
Someone put it like this: a story about three Jewish girls in 1944 who are going to be interrogated and probably raped, now sitting in their Gestapo cell and teasing each other up with stories of what might happen to them in a few hours, and what's happening to their friend right now - that's much too far. But I don't mind stories of POWs, kidnap victims or cops tortured, brutalized and threatened with being killed by goons, even in a realistic setting, that's so generic ( I remmber reading astory years ago called In the line of Duty, about a girl being kidnapped and a police woman who runs into the abductors alone on the highway and is also taken captive in their pickup van,; for two days afterwards the two are kept tied up, whipped and used as sex slaves.

The story was a true turn-on and caught both the brutality of the bad guys, the fear and despair of the police woman and her growing realization that they were going to be killed like drowned cats (in the end, they were saved). No hint of consensus or pleasure on her part, but I loved it and wished it had been me, hands tied, on my knees, sweating, sucking a big dick and a pistol muzzle to my neck.