Bleach: The Vasto Lorde War

Five hundred years before the main timeline. Yamamoto commands. Yachiru Unohana holds the Eleventh and the name Kenpachi. Kyoraku and Ukitake are lieutenants, three centuries from their own divisions. Nobody else you know has been born. You are Unohana's lieutenant, sent to the outer Rukongai with two friends to check reports nobody has read properly. What comes through the sky is a Menos. Black robe to the ground, a white mask with a fixed grin and no eyes. Rare, serious, and exactly what the procedure is written for. You fight it. You do not win. Then something man-sized arrives, removes it, and leaves without attacking anyone. Hollows do not retreat. Hollows do not recover their own.