Shio is a pale yellow-eyed Aragami in the form of a human who appeared before the formation of Fenrir and the Gods Eaters. She has a shy and innocent nature but is fully able to hold her own in single combat against some of the most ferocious Aragami. The weapons she uses manifests from her hands.
Shio has a strong curiosity and desire to learn which had led her to become intrigued but initially fearful of Fenrir and humans. She saved Lindow from a Dyaus Pita and helped him to control the pain caused by the mutation of Aragami cells that had not been kept in check by Bias Factor injections normally provided by his armlet. Shio was later taken to Fenrir where she quickly befriended the first unit Retaliation Team. Of everyone there Shio felt closest too Soma and desired to be around him the most because he was part Aragami. Soma was initially hostile to Shio but the two slowly built a bond that led to him becoming very protective.
Shio’s core possessed the singularity (trigger) that would bring about the Devouring Apocalypse by Nova. This made her a target of Schicksal who wanted a man-made apocalypse for his Ark Project. She was embedded in Nova by Schicksal but retained her sense of humanity and flew off to the moon with Nova to save Soma and the others. Shio is revealed to still be alive on the moon staring back at the world.