"Power is the tool of destruction."
Merlanda Emsworth is human female mage that was born in the town of Lakeshire ten years after the opening of the Dark Portal. When she was young, she was sent to Dalaran to learn with the Kirin Tor to become a mage; she enjoyed life in the great city, and always had rather peaceful motives. During the Trial of the Crusader, when she saw the Horde's actions against the Alliance, she grew outraged and vowed that she would suppress them for their barbaric actions.
Over the next few years, Merlanda worked against the Horde. Eventually her actions resulted in her exile from the Kirin Tor, which she planned on doing herself in time. It was not until after the events in Pandaria that Merlanda's hatred grew strong and unbreakable, and she traveled to Draenor just to deal with the Horde. At one point, she nearly drowned Warspear in a tidal wave, but was stopped by her brother. She left Draenor, and was not heard of again until the Burning Legion's return.
Merlanda traveled to the Broken Isles, seeking an answer to her quest. She came into contact with Kil'jaeden, who bestowed upon her demonic powers to use against the Horde. At some point, Merlanda conjured a felstorm in Stormheim to destroy a Horde encampment, but was once again confronted by Drasgar. This time, however, Merlanda would not back down, and instead a rift was formed, sucking Merlanda into the Twisting Nether and ending the felstorm. There, Merlanda was strengthened even further by Kil'jaeden himself, and then resent to Azeroth to lead their Legion forces.