Ketta Keras is the Supreme Commander of the Metomeus tribe, leading their rebellion against King Fungun's oppressive rule in the parallel world of Byston Well. He commands the tribe's forces and coordinates strategic efforts to liberate enslaved members held at the palace in Izumido.

His leadership requires tactical decisions during escapes, such as deploying decoy groups to divert enemy forces and shield fleeing slaves. He works with Ondel, leader of the food gatherers, who provides stored weapons for the rebellion, reflecting Ketta's involvement in logistical preparation. Ketta places crucial trust in the summoned warrior Garzey's Wing (Christopher Senshu), relying on this legendary figure to aid the tribe against the Ashigaba army and their War Beasts.

Ketta operates within intense conflict, including the death of Ashigaba general Gelgog Aji during a limestone cave collapse, an event within the ongoing struggle between the Metomeus and their oppressors. He maintains command throughout the tribe's journey, interacting with key figures like the priestess Hassan and the warrior Leelince.