Tario was the last Jeddak of the forgotten city of Lothar. Cut off from the rest of the world the handful of surviving Lotharians had developed impressive mental powers that allowed them to create illusory population for their city and warriors with which to defend it from the hordes of Torquas. Tario is the leader of the 'etherealists' and the most powerful mind in Lothar. He is also arbitrary, cruel and tyrannical. When the beautiful Princess Thuvia of Ptarth stumbled upon Lothar with her lover, Prince Carthoris of Helium, Tario wanted her for himself. He attempted to use his mental powers to make her love him, and almost succeeded, but Thuvia managed to escape his spell and stabbed him in the chest with her dagger, unfortunately failing to kill him but putting him hor-de-combat long enough for Carthoris to reach her.
Kar Komak tells Carthoris that Tario has secreted deep in his palace the materialization of a beautiful girl, called the maid of Lothar, who Tario hopes will eventually become permanent and real. Kar Komak hopes for the maid's sake that that never happens.