Crouzade Laia rules as the royal queen of the Dracters, an alien species from the annihilated Planet Sidr. After their home world's destruction, the Dracters traversed space until they encountered Earth. Under Crouzade Laia's command, they executed a catastrophic invasion that eradicated about 99.9% of humanity within 48 hours—an event known as "The Day of Destruction." To adapt Earth for Dracter habitation, they drilled a massive hole through the planet and replaced its core with an artificial one, creating the transformed "Donut Earth." This invasion established her as the primary antagonist in the series' first season.

Her governance enforces a strict monarchy, with Crouzade Laia reigning as supreme ruler over a feudal society divided between nobles (Littel) and commoners (Sheda). The latter are routinely deployed as frontline forces in military campaigns. She exhibits ruthless leadership, extending even to her daughter, Princess Arshem Laia, whom she treats with severity. This dynamic underscores Crouzade Laia’s uncompromising stance on Dracter supremacy and territorial control.

Her role consistently centers on orchestrating the conflict against humanity. Commanders like Grieffas Kredo reinforce her authority, serving as the Dracter army’s supreme commander under her absolute confidence.