The Abysmal King and Queen are away from the Abysmal Palace quite a lot due to the Abysmal Kingdom being so big that they have to help find food for the abysmal fish. Therefore, Bia is usually left in charge of the kingdom in their absence.
In The Ballad of the Forgotten Princess, the Abysmal King and Queen were overthrown by their trusted friend, Thorn, who was a minister in the kingdom. They were kept prisoner in a cell inside Thorn's secret cave while Thorn ruled as the Shadow King and Bia worked to thwart his plans. After Thorn's plans backfired on him, leading to him being arrested, the Abysmal King and Queen were rescued by the Shark King after forcing a confession from one of Thorn's soldiers.