Lilia begins as a princess of Ayodoya who marries Prince Ithaca of the Cosmoralian Empire, ascending to queenship upon his coronation as King Astralta III. She thrives within Astria’s advanced human civilization, gracing royal festivities moments before alien machines invade. After the invaders assimilate Astralta III and other leaders amid global collapse, she gives birth to twins Jimsa and Affle. To safeguard them, she consents to nanny Tarama’s scheme: Affle escapes with gladiator Balga while Lilia flees with Jimsa, sacrificing unity for survival.

Later, facing assimilation by the mechanical civilization, she merges her biology with their technology. Transformed, she champions the machines’ vision—eradicating conflict, pain, and individuality to forge a monitored utopia. She implores her sons to embrace this eternal harmony, embodying "Transhuman Treachery" and "Utopia Justifies the Means."

Despite her conversion, maternal bonds endure. When Jimsa and Affle reject assimilation and flee Astria to preserve humanity, she accepts their defiance. In her final act, she bids them farewell without dread for her own imminent end alongside the machine collective, embracing her fate with resignation.