Mass murder is simply murder of multiple people, more specifically in relatively the same area and at the same time (area to differentiate it from spree killing and time to differentiate it from serial killing). Key word being murder. I.e. unlawful killing of a person. You don't commit murder by killing enemies during war. Even when they are civilians, that's covered by different, more specific crimes that fall under the umbrella of war crimes. Instead of calling bullshit on things you have even less of a clue than you do on Warcraft lore, how about you educate yourself. And again, don't use words you don't understand.