How characters handle visceral violence is something which I feel is handled exceptionally poorly in almost all games (I actually cannot think of a single game that handles it well, but because I haven't played every game I will use the word almost just in case 1 exists). Games go to a lot of effort to provide a multitude of ways for you to kill, maim or dismember enemies, but next to no emphasis is put onto the emotional toll this would take on the character. In my opinion, this is a sorely missed opportunity. To be fair, I cannot blame games entirely for this, most fantasy novels avoid dealing with this topic as well, it isn't easy to write about and it doesn't make for fun reading either, even if it is deeply thought provoking and emotionally moving.
There is a great book called Crime and Punishment which deals with the mental anguish of the protagonist, following on from him murdering a pawnbroker. It doesn't make for light reading, but the depth of the characterization there really does make the reader stop and think for a bit. I am not sure how a similar effect could be conveyed in a game, maybe with dream sequences over the people you kill, or something like that. Either way, dealing with human suffering in the video game format is hard. I don't think Faerun would even be the right setting to attempt to do something like that, not without having a much more focused campaign. For such a story to be effective, you would probably need to first convince the player to view the NPCs within the world as real people, then make them emotionally attached to those people, then force the player to kill them off.
Even if you could do something like this successfully in a tactful manner however, there is a question of whether you would even want to. Most people play games to blow off steam and relax, not to stop and think about complicated moral dilemmas.
The closest game I can think of off hand is Hellblade: Senua's Sacrifice. The protagonist seems pretty compellingly traumatized in that game, and it also deals with psychotic mental illness in a pretty satisfying way. (Speaking as someone who has struggled with psychosis myself.)
I love Crime and Punishment! Dostoyevsky is one of my favorite authors of all time. Raskolnikov's psychological journey is definitely fascinating.
Personally, I'd love to play games to think about complicated moral dilemmas, if more games offered that option.