Nightmare Fuel: The Culture
Iain M. Banks's Culture novels do have some Nightmare Fuel. Given that at their core, they are about a utopian civilization, this is surprising. Spoilers below:
- Look To Windward features terrorists from a civilization the Culture caused a civil war in trying to get revenge. They fail, and the Culture get revenge in the form of a nanotech construct. The first terrorist is ripped apart from the inside out be a swarm of nanotech bugs. They're only on the inside because they forced their way in through his mouth and eyeballs. The second terrorist is flayed alive by the construct, then pushed off a cliff while it still holds his intestines. The moral? Don't fuck with the Culture.
- Consider Phlebas featured the horribly obese cannibalistic eaters.
- In Excession the Affronters genetically modify living beings into literal playthings, such as balls for a tennislike game.
- They genetically modified females of their own species so they find reproduction incredibly painful.
- The entertainment on Azadian TV consists of horrible, sexualised torture in The Player of Games
- The Chairmaker in Use of Weapons has the skeleton of his former lover, his adversary's sister, turned into a small chair, which he arranges to have delivered to his adversary! As if this wasn't horrifying enough, it has a particular effect on the protagonist because it resembles the chair he once walked in on his enemy, once a childhood friend, having sex with her on.
- The Iln warrior-ship from Matter. That such an entity can arrive in the last fifty pages of the book (although not without build-up) and unseat the story's until-then main antagonist as the most disturbing character in the book in a few short paragraphs is no mean feat.