She is also the small orange bird Micaiah owns, and Yune speaks to Micaiah in this form before Micaiah sings the Galdr of Release. If the chaos of war forced her to awake, then Ashera would also awake and Ashera would pass her judgement upon the world. But, if the galdr of release awoke her, then Ashera would have to speak to Yune first before passing her judgement. Unfortunately, Ashera broke this agreement and turned most of Tellius' inhabitants into stone.
After Micaiah sang the galdr of release, Yune uses Micaiah's body to talk to the mortals who would lead her army against Ashera's Disciples of Order.
The Great Flood and the Medallion
When the world was young, the Laguz and the Beorc fought each other. Because of this, the goddess Ashunera flooded the world, except for Tellius. Realizing what she had done, and fearful of it happening again, she split herself into Yune (the goddess of chaos and transformation) and Ashera (the goddess of order and restriction). Ashera believed that Yune had to be silenced, so she and her three heroes fought to seal her away.
Lehran sealed her in a bronze medallion, and it came to be known as Lehran's Medallion, also known as the Fire Emblem. She could only be awakened by a war that engulfed the continent, and the chaos energies that come with it. After being sealed away, Dheginsea framed her as a dark goddess to instill a fear of war in the people, and prevent Yune's release. He also strictly forbade Goldoa and its people to be involved in any wars, taking a strict neutral stance, as an additional preventative measure.
Role during and before in Radiant Dawn
After The Mad King's War, Yune appeared to Micaiah in bird form and landed on her finger. The word "Yune" popped up in Micaiah's head after this, and the bird had been called that ever since. She is also the one who contributed to Micaiah's foresight.
Throughout Part One of the game, Yune was Micaiah's constant companion. Later in the game, she became the "voice" guiding Mist and the Herons to awaken her with the Galdr of Release.
After Ashera sent her judgement upon Tellius, Yune, who is released from the medallion, periodically possessed Micaiah to use her body for a number of things, which included promotions (Ike, Sothe, and Micaiah respectively), and telling of the history of Tellius in the Tower of Guidance. After Ashera is defeated, Yune is able to appear in her goddess form, and, after a short conversation with Ike, she transforms back to a bird and flies over Tellius to restore the petrified people.