Spirit of the Tree of Ages

"Its vital life-force has remained dormant all these years and is now being awakened by the Tree of Ages."

- Kikyō to Kagome

The Spirit of the Tree of Ages is the very essence of the Sacred Tree of Ages itself from both timelines. It had remained dormant for the entire anime of InuYasha.

History
During the events from when Kikyō pinned Inuyasha to the Sacred Tree, the spiritual energy within the arrow tip was infused with the priestess's own vital essence. This said essence was absorbed by the Tree, enabling it to take on the appearance and voice of Kikyō.

While watching over a sleeping woman in the core of the tree, it detected the arrival of the half-demon princesses and asked the girls a request to slay the Eastern beast king Kirinmaru.

Many months later, Moroha tries and fails to get it emerge again as the Half-Demon Princesses had just encountered and fought Kirinmaru on her behalf.

Personality
Being infinitely wise and knowledgeable, it also seems to have acquired a bit of Kikyō's personality as it has taken on her form to commune with Sesshōmaru, and his twin daughters and niece.

Physical Description
It has no known form but has since borrowed the form and voice of the late priestess Kikyō.

Trivia

 * In the Avatar franchise, there is the ancient Tree of Time of the Spirit World, where the very first Avatar, Wan, had permanently merged with the mighty Spirit of Light and Peace, Raava, who was then transformed into the Avatar Spirit. Avatar Wan had then imprisoned the Spirit of Darkness and Chaos, Vaatu, inside its hollow for the next ten millennium. The Tree of Time remembers everything in existence.
 * Despite its wisdom, the spirit seems to get some facts mixed up, or possibly distorts the truth. Kirinmaru at present is content with his territory, with Zero being the only real threat.
 * It seems the spirit made a pact with Sesshōmaru to watch over Rin; given he can freely enter the dimension within the Tree of Ages. It also gave Jaken the instructions on how to prevent Rin's third and final premature demise via Zero's silver-scale curse by connecting Rin's youngest twin daughter to Rin via a Dream Butterfly.

Media Appearances

 * Episode 4 (Hanyō no Yashahime)
 * Episode 8 (Hanyō no Yashahime)
 * Episode 27 (Hanyō no Yashahime)