Mercenary, Assassin, Hitman? [He waves a hand after making the list--it's not really important. Wick has the expression enough of a man who's been through shit and has done some shit. So in the end, it doesn't really matter.]

I have a feeling that if we go outside the walls to work together, I won't so much have to tell you who to kill as we'll come to an agreement for what needs to be killed.

[After all, the monsters don't much have a problem with running head-long at the first thing that looked edible.]