Kaede

Kaede was a former Priestess of Amatsu and the Fire Witch, who fought alongside Elcrest one thousand years prior to the main events of the story.

Prior to Main Events
A thousand years prior to the events of the main story, Kaede was a Priestess and became the Fire Witch at some point during the period of the second Eclipse. She was met by Elcrest and was tuned by the Conductor, becoming his ally. Accompanying Elcrest with the four other witches, the Forgotten King Xeno, and Technolomy Veronica, the group would battle the Angels and ascend to the Moon in order to stop the Eclipse by defeating God. It is hinted that Kaede cared greatly for Xeno. On that fateful day when the group would ascend the Yggdrasil and reach the Moon, Kaede would witness God, in reality the Mother Qualia, afflict Elcrest with a severe strain of negative energies. When Xeno sacrifices himself to save Elcrest, Kaede makes a desperate attempt in saving him by reaching out to the King as he withstood the concentration of negative energies. Despite their reluctance in leaving him, especially Kaede's, the group is warped to safety by Hilda.

As the afflicted Elcrest suffered and begged his companions to kill him, Kaede looks to Ukuna to save him, though the latter expresses her doubts in being able to do so. When Francisca proposed she put him into a deep slumber within the waters as means of purification, the other Witches would agree with her plan and go their separate ways.

In the aftermath of the Eclipse, Kaede would continue her duties as a Priestess. Before she passed away, she would record the Fire Score, her part of the Celestial Hymn, on a scroll that would be stored in Amatsu shrine's inner sanctum.

Chapter 10 - The Celestial Hymn
Kaede appears in Hilda's flashback, as she shows Alto the events that transpired a thousand years prior during the second Eclipse.

Her shadow also appears in Alto's spirit world along with the other past Witches, embittered that the group had left Xeno to die.

When the Tuning Knights search for the dispersed scores of The Celestial Hymn, they arrive at Amatsu to search its shrine. Nonoka is sent to venture the innermost part of the shrine, as even Priestesses were forbidden from entering, which connected to a cave in Gohra Volcano. Nonoka returns with a plethora of scrolls, with one in particular resonating with the Fire Qualia. Kaede appears before Sakuya in a vision, her spirit having resided in the scroll, where she states her belief that her descendant would not repeat the former's mistake of having to sacrifice an ally. Kaede bestows the Fire Score to her descendant and also makes a personal request to Sakuya, that she along with her allies "save [Xeno's] soul".