Fila Marique is a council member of The Third, the mutant rulers distinguished by their third eye who control Earth's technology in a post-apocalyptic world. She works closely with fellow councilor Joganki, though their methods frequently diverge; Fila favors swift and occasionally severe decisions, contrasting with Joganki's approach, which is often swayed by his personal interest in the protagonist Honoka. Despite these differences, they maintain mutual respect.

Her demeanor remains consistently serious and formal, projecting a regal bearing befitting her authority. Beneath this composed exterior lies a capacity for subtle kindness, expressed quietly. Fila commands significant political power, demonstrated when she swiftly deployed military forces to intercept Honoka and Iks near the Steel Gorge.

A crisis erupts when Joganki disappears during a diplomatic mission, captured by the rogue Third member Rona Fauna. Fila personally recruits Honoka for the rescue, recognizing Rona's ability to control autonomous enforcers like Blue Breaker necessitates Honoka's unique combat skills. For this mission, Fila assigns Blue Breaker as Honoka's backup, despite Honoka's reservations. Fila's primary concern extends beyond Joganki's safety to preventing Rona from activating the devastating orbital weapon, the Wormhole Driver.

Throughout this operation, Fila's trust in Honoka grows as she observes her capabilities firsthand. Her analytical mindset and commitment to The Third’s principles guide her decisions, prioritizing the containment of dangerous technology under the Technos Taboo. Her actions consistently reflect her role as an enforcer of The Third’s authority.