First off there are only two cards I would seriously consider out of this pack, Nighthawk and machete. Malakar and Shepard are both good cards, but they are both a notch below the other two. The only removal in the pack is into the roil, which is decent, but nowhere near pick one material.
If you take the Nighthawk, then you are committing to heavy black because of the two colored mana cost and the fact that you want to cast it on turn 3 if possible. Also, passing the bloodwitch means that one of the drafters immediately after you will go into black. In order to make taking Nighthawk work I would start drafting black aggressively if at all possible. Black is the best color in Zendikar though, so this strategy could blow up if nothing good gets passed to you.
The other option is to take the machete and wait to see what comes your way. The first pack has no decent red, so if you get passed some it should be possible to claim that color and get decent cards passed back to you in pack two.
I would probably go with the nighthawk in this scenario. It's a bit riskier, but has the potential to lead to a more powerful deck.
P.S.
Aren't there two cards missing from that pack?