Dar'Khan Drathir is an elf who betrayed his people and a villain in Warcraft.
Dar'Khan was a member of the high elf council that ruled Quel'thalas. When word came that Zul'jin tried to invade Quel'thalas, he dismissed that they wouldn't be able to get past the protective runestones that protect the land. Dar'Khan was also a friend of Lor'themar Theron and a magister of Silvermoon. As a magister, he helped build cities in Quel'thalas.
Dar'Khan was secretly obssesed with the Sunwell and began learning dark magic. He eventually joined the Lich King and helped him with his goals especially in helping the Scourge invade Quel'thalas. After Kel'Thuzad was resurrected, Dar'Khan was killed by Arthas and raised into an undead. Dar'Khan was tasked by the Lich King to oversee the forces of the Scourge in the Ghostlands.
Years later, he was confronted by adventurers from Silvermoon. Dar'Khan sent two of his necromancers before he confronted them himself. In the end of the conflict, Dar'Khan was killed and his head was brought to the regent lord.