Frixio is the elder of the sylphs that fled to Little Solace following the schism in the Sylphlands. He is initially absent when the adventurer, Yda, and Papalymo arrive at Little Solace to assess the risk of Ramuh being summoned into Eorzea. It is eventually learned that Frixio and a few sylphs had fled into South Shroud to evade Garlean soldiers from Castrum Oriens, with the elder taking shelter inside the Thousand Maws of Toto-Rak. The adventurer finds him imprisoned in a diremite web by Lahabrea in the depths of the dungeon.
Frixio also appears in the Sylph Beast-Tribe storyline, having to suffer the company of the inept scholar Voyce. They explain the legend of the "Chosen One," a sylph podling of immense power born once a millennium. Frixio and the other sylphs are rightly concerned about the Chosen One falling into the hands of touched sylphs and becoming tempered by the Lord of the Levin, and ask for aid in delivering it safely to Little Solace.
During the Beastman Alliance quest line, Frixio accompanies Hamujj Gah, Sezul Totoloc, Clutchfather Novv, and 789th Order Pickman Gi Gu to the showdown against Memeriga and his hired sword Nhaza'a Jaab.
Frixio appears on a card in the version available via Final Fantasy Portal App.