The Oracle is an aspect of Lyra, that arrives at her highest point of magickal prowess, during the Blue moon. She doesn't carry her crescent blade but mostly revolves around magick of opposing forces together. But her true power is seeing and tuning the weaves of fate.
Her appearance and time is to harness the magic and soul to heighten their potential. As a time of peace and preparation for the spirit. But ultimately to promote balance and calm.
Despite being the most peaceful of Lyra's forms, she will fight only when necessary, and only fight with as much force as needed.
But her presence instills a calm and ease for many, but also keen awareness.

A couple of fun facts:

Underneath her dress, only her upper body is physical while her lower body is spiritual.

And the hue of her three eyes, at her veil's crown, are the same color as the third eye chakra. Meant to add other pantheon influences despite her greek origin. Combining the triple moon symbolism of her teacher of magick, and also the spiritual power and self-reflection allowed by the third eye chakra.