Mushi

Mushi is an " Onna-musha ", an ancient Japanese warrior, the female counterpart of the " Samurai ". Fed up with the deaths of so many samurai at the feet of that fearsome kitsune, she decided to defeat him, who apparently not only murders anyone who enters his forest, but also terrorized villagers who lived nearby.
She is 27 years old

Sword proficiency: Mushi wielded a katana in the past. She was likely quite adept; a battle with Mystery depicted the kitsune bloody and bruised while Mushi was relatively unscathed and still armed.
Endurance: Mushi had to be very enduring because facing Mystery shouldn't have been easy, surely very fierce. One of the skills her descendant Vivi inherited from her.
Speed, Reflex and Agility: Mushi was very fast, lively and agile, capable of acrobatics, jumping and skillful landing. From memories or visions of the past, Vivi seems to have inherited her agility and fighting style as well.
Cryokinesis: Mushi appeared to have ice magic that she could channel into her katana. In the flashback with Mystery, snow was on the ground whereas the previous scene confirmed the setting was not in winter. Furthermore, in "The Future", Mushi's spirit manifested in a snowy forest when she met Vivi. After Vivi accepted her help, her baseball bat generated the same glow as Mushi's katana did and could produce ice.

Mushi seems to have a rather stoic presence, but will aggressively defend those she feels the need to protect. She is bold and confrontational towards a very powerful looking Mystery in kitsune

Mushi has a petite yet athletic body, sky blue hair with bangs, and a long raised ponytail. She has a scar on her cheek under her left eye, as well as another on her upper left arm. She wears a long blue scarf, an Alice blue gi with torn sleeves, and a darker blue chainmail shirt. She wears mauve bracers and leg wraps.

Her physical appearance is eerily similar to Vivi, though she has noticeable differences in hair shape, clothing, and a more serious and battle-hardened demeanor.

Mushi carries a blue katana with tassels on the pommel and gold diamond patterns (tsuka-ito) on the handle, with the guard (tsuba) bearing a strong snowflake motif. It glows with an otherworldly blue essence that might be connected to the ofuda wrapped around Vivi's baseball bat.