So, portals, how do they work? I can understand how a mage from Orgrimmar can put portal to Silvermoon and simply walk through it, thats ok. But why no one used mages (correct me if im wrong) to invade another city? Why Horder didnt gathered their army and simply put 10 portals to silvermoon to swarm this city? Why we needed the whole Dark Portal to get from Azeroth to Draenor, and when we set up our garrison Khadgar puts a portal to another timeline (!) with no effort. Why mages can't put portal to most zones, whats the difference?