Yasha has purple hair and eyes, and shares some design elements with Fubuki's Mother, though she lacks the protruding ears.
In place of arms, she has long, feathery wings, though she is still able to use her twin staves as weapons. She also has bird legs instead of human legs.
Her outfit is very elaborate and resembles that of a priestess.
At first this presented itself with Yūyaki's personality occasionally having dramatic shifts. However, eventually Yasha managed to break out of her seal and take over Yūyaki, leaving the cast split on whether they should kill Yūyaki in order to stop Yasha.
Eventually, Yūyaki managed to make a truce with Yasha and regained control of her body. Now, with the aid of Yasha's power, Yūyaki can assume a super form like other faction leaders (ie. Ultimate Asuka, Crimson Homura, etc.).