Yin and Yang

The two look almost like mirror images, set apart mainly by their hair: Yang wears hers short and red, while Yin keeps a long blue mane braided into thick front locks. Both share the same aqua eyes rimmed with shadow and a mask fragment that runs like a vertical band down the center of the forehead, doubling as a horizontal sheath for their weapons behind the head.

Their matching outfits echo the white Arrancar uniform, trimmed with sleeveless jackets, elbow gloves, stockings, high-heeled boots, and short skirts, done in red on Yang and blue on Yin, and each conceals a Hollow hole on the chest.

Little emerges of the pair beyond their unwavering devotion to Sojiro Kusaka, whose cause they serve without hesitation. They act as a single coordinated unit, one striking with lightning and the other with flame, and follow his orders to the letter, even accepting the icy fate he inflicts on them once they are beaten and injured.

Both Arrancar carry high spiritual power expressed through their elements, Yin as blue lightning and Yang as reddish-orange fire, and both move with capable Sonido. Yin wields a jian that unfurls into an electrified whip and can compress lightning into hurled balls, even collapsing herself into fast-spinning electrical spheres. Yang fights with a flaming blade, conjuring destructive fireballs that once matched the force of Sado's El Directo, and can likewise become a rolling ball of fire. Working together they merge their opposite elements into combination strikes powerful enough to rival a Getsuga Tensho, and by unknown means they can summon large swarms of Hollows.

After Kusaka seizes the Oin he reshapes them into giant Hollow forms that fire elemental Ceros, loose weaker Bala-like bursts, and regenerate from otherwise fatal wounds, a resilience Mayuri attributes to the Oin blurring the line between life and death. Sent against the invaders, they injure Ichigo and clash with the Shinigami until they, and Kusaka, are finally undone.