Medivh ("keeper of secrets" in Thalassian)[21] was the last Guardian of Tirisfal, an ancient line of protectors bestowed with great powers to do battle with the agents of the Burning Legion. He was possessed even before birth by the spirit of the lord of the Burning Legion, Sargeras. Under his influence, Medivh contacted the orc warlock Gul'dan, and together they opened the Dark Portal, bringing the Old Horde to Azeroth. He was slain some time after by a party led by his best friend, Anduin Lothar.

Resurrected by his mother Aegwynn, Medivh returned as a mysterious prophet shortly before the beginning of the Third War, manipulating events in order to arrange the formation of a last-ditch alliance between the mortal races of Kalimdor, guiding them to victory at the Battle of Mount Hyjal.[22] To this day, Medivh's soul remains within the haunted tower of Karazhan. Fragments of his soul have been known to challenge or provide guidance to those who brave the tower's dangers.