your fantasy world was all humans, intrigues, politics and naturalism above ground ... and only in the Underworld did monsters dwell?
And those monsters were there in large numbers, and killable without remorse, because ...
- they were less than human, and you needed their gold and experience points.
- they were intrinsically evil and needed to be wiped out.
- they were threatening the world above, and you needed to save the village.
I'm working out these three implications in a different context than games - an article I'm co-writing in psychology, about how terrorists, extremists, and other supporters of violence overcome the natural impediments against direct killing of another human being. I suppose there are other answers, such as ...
- the characters are sociopaths, born or made (viz. Raggi's fighter class in Flame Princess)
- the characters are heroes who need impediments to overcome
- the monsters deserve it; they chose to be monsters
- the characters do feel remorse; they lose Sanity or Humanity each time they have to kill a sentient being
- the whole situation is an ambiguous allegory in which each of these possibilities can be considered
I want to find the balance that Umberto Eco found, in one of his essays when he contrasted the very physical war games he used to play as a boy with the cold sadism of the entirely bloodless genocide, the future Auschwitz commandant playing with the Erector set.