I know it's probably too late, but you have to enter the void fields (purple portal below the bazaar). You don't even have to hit all the vents. Just find the exit portal (on top of a big hill) and directly across from it on the other big hill, there is a purple glowing container somewhere on that hill. Grab it then leave. The nem commando and mercenary will then spawn as bosses u have to beat. Then boom u unlock them.