Having a cynical outlook as a result of his occupation and being kind can sometimes collide though. When he sees a damsel in distress, does he think "I need to help her" or "It's a trap"... or, does he perhaps think "I'm going to help her even though it's probably a trap." Basically, is he kind in spite of his cynicism? 

It's sounding so far like his apathy is applicable only in situations where there is a lot of death or violence. A better way to describe it might be to say that he is hardened against such things, rather than apathetic. Apathy suggests that if a child he was supposed to protect dies, he wouldn't care at all. If that is the case, then apathy would be the accurate word, but I get the feeling that isn't what you're going for. Perhaps he is only apathetic towards those he deems evil-- or those he is being paid to kill? (Mercenary work is not always the most just-- does he reject jobs if he is hired to kill someone he deems innocent or does he approach it with more of a "Sorry, it's strictly business" approach?)