Onia, also known by the alternate rendering Conia, is a former grunt of the Explorers who served as a subordinate to Amethio and initially appeared as an antagonist. Despite her role within the antagonistic organization, she possesses a warmhearted personality, which she often conceals. This was evident when she cared for a captured Sprigatito, providing it with food and toys. She became embarrassed when Amethio witnessed her playing with the Pokémon, having expressed a desire to keep it for herself rather than engage it in battle.

Onia demonstrates strong loyalty to Amethio, remaining by his side even after his dismissal from the Explorers, alongside another subordinate named Zirc. Her involvement in the narrative includes pursuing the protagonist Liko aboard an airship in an attempt to obtain her pendant. During this mission, Onia was tasked with luring the pursuing crew to the Explorers' hideout and was directly responsible for the care and transportation of the captured Sprigatito.