Jilltail is a leader of the antagonistic organization Chaos Choir. She is an Edel Raid, capable of fusing with humans to form living weapons. Her appearance features long white hair, a dark complexion, and an Elemental Gelade gem signifying her power on her left shoulder.

In combat, Jilltail reacts with Sting Raids, artificial counterparts to Edel Raids. This reaction unfolds spider-like legs from her back, augmenting her offensive potential. She primarily attacks using whip-like strikes.

A significant event involves Jilltail and fellow leaders Aljeena and Orfus severing the protagonists' Cou and Ren's bond. They initiate a reaction with Ren to harness her power for Chaos Choir's goals. This process is forcibly broken when Cou and Ren unite to sing a forgotten song.

Following this confrontation and the defeat of Chaos Choir's plans, Jilltail abandons the organization. She aligns with Arc Aile, an organization dedicated to protecting Edel Raids, signifying her participation in working toward peaceful coexistence between humans and Edel Raids.