Bynas commands the sand pirates' vessel Bardanos (or Baldanos) in a future Earth reduced to a desert wasteland by solar radiation. Her attire features a flowing cape and scarf, reflecting the series creator's artistic style. She exhibits decisive leadership during submarine-style sand engagements against Theseus forces, prioritizing crew safety and mission objectives through maneuvers like hazardous silent running to evade detection.

A significant personal history connects her to Dick, brother of protagonist Sam Coyne, who vanished during an earlier Ozma expedition. This fuels her protective stance toward Sam and informs her grasp of the conflict between Ideal Children clones and Naturas. The revelation that Theseus commander Gido Gaira appropriated Dick's body via technology further complicates her motivations.

Her role intensifies during the pursuit of Maya, a genetically significant target of Theseus. Bynas coordinates the Bardanos's protection efforts against escalating threats from military forces and the sand whale Ozma. In Ozma's nest—an underground sanctuary with water and life—she confronts Gido, strategically exposing his true identity.

During the resolution, Dick briefly regains control of his body after Gido's injury. He communicates a coded farewell to Bynas using knowledge only he possessed, concluding their dynamic.