Rosalia de Cartagena serves as Angelique Limoges's chief rival in the Queen Examination, the competition selecting the next Queen of the Cosmos.

Her aristocratic bearing and refined demeanor starkly contrast Angelique's ordinary background, cultivated through rigorous, dedicated training since birth specifically for the Queen Examination.

This lifelong preparation focused on mastering Sacrea, the cosmic powers granted by the nine Guardians. The examination's core objective demands candidates wield these powers to cultivate a barren continent, with victory determined by whose developed territory first reaches the central connecting island.

The contest's structured nature, involving strategic resource management and territorial expansion, aligns seamlessly with her methodical upbringing. However, the nine Guardians introduce interpersonal complexity, requiring candidates to navigate relationships with these powerful entities while balancing power accumulation and personal connections.

Groomed explicitly for this role from birth, her background implies immense pressure to succeed, positioning her as a formidable contender within the high-stakes contest for the queenship.