Lyones Theo Earthlight rules the lunar Kingdom of Sphere, a nation founded by Earth migrants. Originally a commoner student at Lunar College, his romance with Princess Cefilia sparked controversy due to their differing status. Encouraged by an Earth diplomat later identified as Tatsuya Asagiri's father, he pursued and married Cefilia, ascending to the throne.

After Cefilia's death, Lyones raised their daughter, Feena Fam Earthlight, alone. His reign prioritizes justice and stability between the historically strained Moon and Earth, nations marked by past conflict like the Oedipus War. He actively prepares Feena as heir, instilling her late mother's values of fairness, kindness, and diplomatic reconciliation, driving his governance and parenting to fulfill Cefilia's dream of peaceful Earth-Moon unity.

Lyones exhibits a reserved, analytical personality, often perceived as aloof or emotionally distant, traits potentially shaped by his responsibilities. Psychological assessments categorize him as an ISTJ and Enneagram Type 5w6, manifesting in meticulous statecraft, strategic military planning, and a preference for solitude. Despite his reserve, he demonstrates underlying care for Feena's well-being and development.

His relationship with Earth remains complex. While committed to diplomacy, he navigates a political climate demanding caution. He demonstrates trust in specific Earth individuals through his acceptance of Feena's homestay with the Asagiri family, whose patriarch once supported his courtship. His role in broader political events between the two worlds is undocumented in the available sources.