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Gerun is voiced by Bernice Stegers in the English version and Seiko Tomoe in the Japanese version.
In ancient times, Gerun granted the Sword of Kings to the hume Raithwall to become their proxy in determining the course for Ivalice and manipulate history to their own ends. Raithwall obtained three shards of deifacted nethicite from the Sun-Cryst, the Occuria's magicite of power, to become the Dynast King, and played his part well in Gerun's ploy.
700 years later, the heretic Venat trespassed into the hume realm, granting them means to create their own kind of nethicite and control their own history. Gerun turned to Princess Ashe, the descendant of King Raithwall, to destroy Venat and the Archadian Empire - the judgment for making imitations and trying to control their fate.
Luring the princess with a specter of her dead husband, Gerun hoped to fuel Ashe's hatred for the Empire enough to have her destroy it. The princess sees through Gerun's motive, and refuses to be manipulated. Instead, she has the Sun-Cryst destroyed breaking the power of the Occuria over Ivalice.