"Armor usually protects vital organs or other such important features. As of now, we only have one piece of armor on the grimm that is apparent." he said and pointed to the face mask. "This is the only solid appearing structure on the creature, therefore you must either punch through the mask or get around it from another angle. "One could assume that hacking at the rest of the mass might merely be a waste of time as the grimm itself has not bothered to armor it either."