What really starts to sink in on culmination of season two is just why Qilby is so insane. Prior to his first imprisonment, it is understood that he had lived for over 700 years. Growing insanity from being unable to forget ANYTHING, he is in the white dimension for 10,000 YEARS. ALONE. he has spent most of his eternity alone, unable to die, unable to heal his arm, and cut off from (depending on how it's read) the only other being like him, his sister. No goddamn wonder he goes so insane
Also you have to understand from his perspective: a scientist who was stuck on a planet of eternal bliss without conflict, without enemies, without any problem could drive anyone insane.
While he was rather respected by the Eliatropes, he craved novelty, adventure and discovery and probably resented his people for living on a "small" planet, a Gilded Cage.
When the Mechasm arrived, he probably was on verge of despair ready to do ANYTHING to have something new: in a certain way he might have launched a war by complete accident For Science! or simply gone the Despair Event Horizon or Moral Event Horizon since nobody cared for his eternal memory.
When they arrived on the World of Twelves, they have created a monarchy in order to coverup their true past and named Yugo their king: the same warrior who has failed to protect their orignal planet and simply to prevent Qilby using his influence on the children.
Having being denied the right to tell the truth about their history and feel rejected once again, he might have snapped and tried to settle the score once for all with the Mechasm who were hunting them.
Really, Qilby has really gone off the deep end but if you were stuck on paradise and now can't espace, what will you do to live again?
See the page on Qibly History :