Blackwall's lopsided smile is less about finding humor in what Zevran is saying and more in finding his actual laughter and bright smile somewhat contagious. The answer itself is something of a relief and, if he wasn't wearing his weight in wet armor, the assassin probably would've noticed just how much the news seemed to relax him.

"Well, that's more than most. I don't think anyone can fault you for valuing your own life," He clears his throat and offers out a thickly gloved hand to shake, "Warden Blackwall. A pleasure to make your acquaintance.

I hope it's not too forward of me, but if you're running an errand for the Wardens it only feels right to offer my assistance, if you'd have it."