Avexis is a young elven mage from the White Spire Circle of Magi in Orlais, approximately ten years old. She was kidnapped by blood mages led by Frenic, who subjected her to a harrowing ritual involving force-fed drake's blood to awaken her latent magical abilities. This ritual specifically targeted her unique gift for controlling small creatures, intending to amplify it to control multiple dragons while she remained under blood magic thrall.

Rescued by Seekers, High Seeker Aldren ordered her detained for investigation. Suspecting a conspiracy within the Chantry, Seeker Byron facilitated her escape from custody. During these events, her abilities fully awakened, enabling her to direct dragons despite Frenic's earlier control. At the Ten Year Gathering, she reversed Frenic's dominance over the dragons and directed one against him, contributing to his defeat.

Years later, by 9:41 Dragon Age, Avexis reappeared in Haven as a Tranquil, having undergone the Rite of Tranquility. She explicitly stated she "no longer talks to dragons" and declined the possibility of reversing her Tranquil state, citing concerns about demonic possession and emotional distress stemming from her experiences as a mage. This transformation marked the conclusion of her known story, as she disappeared from Haven following the relocation to Skyhold.