ever wonder who was ner’zhul? i always did!!! here is what u might need to know about.
 

Ner’zhul was introduced in Warcraft II: The Tides of Darkness. Initially, he was to be the first Orc to make a pact with the Demon Kil’jaeden but backed out at the last minute. Gul’dan, his second in command, fulfilled Kil’jaeden’s pact, and was responsible for bringing the demonic Bloodlust upon the Orcs. This Bloodlust was instilled in the Orcs when their Chieftains drank the blood of the Pit Lord Mannoroth, in exchange for their services in conquering Azeroth and the Human kingdom.
 

Kil’jaeden taught Ner’Zhul the art of Warlock magic, which replaced the Orc’s elemental Shamanism. Ner’Zhul in turn trained other Orcs in the ways of Warlock magic. His most prominent apprentice is Gul’dan. While The Horde invaded Azeroth, Ner’zhul remained in Draenor as chieftain of the Shadowmoon Clan, with the aid of his enforcer, the Ogre-Mage Dentarg. Later, Ner’zhul wanted to break his pact with the Demons and keep his people from killing each other. The reason for this is that he wanted an army of his own for the purpose of conquering new worlds. Ner’zhul also opened many portals to other worlds from the Orcish homeworld of Draenor; eventually causing Draenor to shatter and fall apart due to the instability of energy created by the rifts.
 

For his insolence Ner’zhul watched in horror as Kil’jaeden and his minions destroyed his body and tortured him by keeping his soul intact, frozen in a block of ice. Ner’zhul begged Kil’jaeden to grant him death but the demon would only agree if Ner’Zhul agreed to another pact which again doomed his entire race to enslavement. The block of ice was sent to crash on the continent of Northrend, becoming buried deep in the ground. Ner’zhul was to become the Lich King - he was to engineer the Undead Scourge using his telepathic powers to do what he previously failed to do - as his punishment by the Burning Legion.

As the Lich King, Ner’zhul recruited Acolytes, including the wealthy Dalaran mage Kel’Thuzad, to assist him in creating the Plague. The Plague later spread across the Human lands of Lordaeron and its neighbors.