Warcraft II: Beyond the Dark Portal

Following the devastation of Azeroth's Dark Portal by the triumphant Alliance, the orc shaman Ner'zhul had taken control of the Horde still left on Draenor. There, he devised a plan to build portals to other pristine worlds and invade each in turn. To make it possible for the rituals for his dimensional invasion, Ner'zhul directed orcish forces through his world's undamaged Dark Portal seeking of the most powerful relics on Azeroth. Cautious of the Horde's ideas, the heroes of the Alliance breached their way into Draenor to put an end to the orcish threat forever. Confronting certain demise at the hands of the Alliance, Ner'zhul was successful in opening up several portals to new worlds. The resulting magical strain destroyed Draenor, trapping numerous of Azeroth's very best heroes on Outland, the damage remains to be of the planet.