Avexis is a mage of the White Spire Circle of Magi in Orlais. She is ten years old.
Avexis is kidnapped by a group of blood mages lead by Frenic. They force-feed the captive Avexis fresh drake's blood. After Seekers rescued her from the blood ceremony, High Seeker Aldren decides to detain Avexis pending further investigation. Questioning the High Seeker's motivation, and suspecting a conspiracy from within the Chantry, Byron decides to take Avexis from her holding cell that night; escaping to nearby woods with Cassandra following close behind.
It is later revealed that she is a Circle Mage with a gift that allows her to control small creatures. Frenic and his group had kidnapped her from the White Spire. Their blood ceremony was intended to fully awaken her ability, enabling Avexis to influence multiple dragons even while enthralled under a blood mage's mind control. Frenic succeeded in initiating the dragon flight attack on the Ten Year Gathering until Cassandra, Galyan, and Alte intervened; breaking Frenic's control over Avexis. Now free, Avexis was able to use her fully awakened ability to direct a dragon against Frenic.