I think death is to some degree a desensitized thing in a world where being old is a rarity because people die to violence more often than they don't. That and each character's background would affect how they view death and killing. A first kill could be a simple rite of passage in one family or a nightmare-inducing trauma in another.
For someone playing the mercenary- help the city deal with bandits, help the Grand Company deal with Garleans -type of adventurer who has willfully chosen that type of work and knows what's involved, killing another person who has been deemed "in the wrong" is probably less of a big deal than for characters who stay out of that line of work. But if a young person who's never killed anyone before chooses to do that kind of thing, if they have any empathy at all and haven't had their choices directed by their past (vengeance, hatred, whatever), I think it probably should affect them at least the first time they kill someone, however briefly, while they work out if it's something they're capable of doing regularly.
As for my character, she lost part of her family the usual Calamity way. That didn't get her down too much, but it did drive her to a mercenary type of lifestyle. While she would have valued most lives very highly, she probably cut her first other-person kill on Garleans in the Shroud, who to her would have been absolutely worthy of any death she could have handed them, and probably viewed killing them as no different than culling an overpopulation of morbols.
When she was later forced into a situation where she had to kill people she knew and loved to make it out alive, she went off the rails and lost all sense of value in life, including her own. She worked as a straight up assassin, killing any target for the right price, because she was good at it and every kill seemed to keep her alive.
She came out the other side of that and has regained her sense of "every life has value," but not entirely intact and undamaged mentally. She still does mercenary work, but is much more careful about which jobs she takes, avoiding murder entirely and probably only accepting kill-type jobs if rescue is involved. So she's been dramatically affected by her life as a "killer," but not at all in the same way as, say, I would be.
For someone playing the mercenary- help the city deal with bandits, help the Grand Company deal with Garleans -type of adventurer who has willfully chosen that type of work and knows what's involved, killing another person who has been deemed "in the wrong" is probably less of a big deal than for characters who stay out of that line of work. But if a young person who's never killed anyone before chooses to do that kind of thing, if they have any empathy at all and haven't had their choices directed by their past (vengeance, hatred, whatever), I think it probably should affect them at least the first time they kill someone, however briefly, while they work out if it's something they're capable of doing regularly.
As for my character, she lost part of her family the usual Calamity way. That didn't get her down too much, but it did drive her to a mercenary type of lifestyle. While she would have valued most lives very highly, she probably cut her first other-person kill on Garleans in the Shroud, who to her would have been absolutely worthy of any death she could have handed them, and probably viewed killing them as no different than culling an overpopulation of morbols.
When she was later forced into a situation where she had to kill people she knew and loved to make it out alive, she went off the rails and lost all sense of value in life, including her own. She worked as a straight up assassin, killing any target for the right price, because she was good at it and every kill seemed to keep her alive.
She came out the other side of that and has regained her sense of "every life has value," but not entirely intact and undamaged mentally. She still does mercenary work, but is much more careful about which jobs she takes, avoiding murder entirely and probably only accepting kill-type jobs if rescue is involved. So she's been dramatically affected by her life as a "killer," but not at all in the same way as, say, I would be.