Just like how it works for Archers.
I suggest this because of my experiences as a Bokor. Hex is a single-target skill that needs to lock on to a monster to work. The problem here is that it’s so hard to pick out a single enemy if it’s surrounded by a ton of zombies. You have to enable target lock, run right at the monster, keep running around, and then pray you lock on to the monster that’s encircled by all your zombies.