Of the two races, Kilâ€™jaeden saw that the warrior orcs were more susceptible to the Legionâ€™s corruption. He enthralled the elder orc shaman, Nerâ€™zhul, in much the same way that Sargeras brought Queen Azshara under his control in ages past. Using the cunning shaman as his conduit, the demon spread battle lust and savagery throughout the orc clans. Before long, the spiritual race was transformed into a bloodthirsty people. Kilâ€™jaeden then urged Nerâ€™zhul and his people to take the last step: to give themselves over entirely to the pursuit of death and war. Yet the old shaman, sensing that his people would be enslaved to hatred forever, somehow resisted the demonâ€™s command.
Frustrated by Nerâ€™zhulâ€™s resistance, Kilâ€™jaeden searched for another orc who would deliver his people into the Legionâ€™s hands. The clever demonlord finally found the willing disciple he sought Nerâ€™zhulâ€™s ambitious apprentice, Gulâ€™dan. Kilâ€™jaeden promised Gulâ€™dan untold power in exchange for his utter obedience. The young orc became an avid student of demonic magic and developed into the most powerful mortal warlock in history. He taught other young orcs the arcane arts and strove to eradicate the orcsâ€™ shamanistic traditions. Gulâ€™dan showed a new brand of magic to his brethren, a terrible new power that reeked of doom.
Kilâ€™jaeden, seeking to tighten his hold over the orcs, helped Gulâ€™dan found the Shadow Council, a secretive sect that manipulated the clans and spread the use of warlock magics throughout Draenor. As more and more orcs began to wield warlock magics, the gentle fields and streams of Draenor began to blacken and fade. Over time, the vast prairies the orcs had called home for generations withered away, leaving only red barren soil. The demon energies were slowly killing the world. Turalyonâ€™s forces succeeded in destroying the Dark Portal, the mystical gateway that connected the orcs to their homeworld of Draenor. Cut off from its reinforcements and fractured by infighting, the Horde finally buckled in upon itself and fell before the might of the Alliance.