This Corpse Is Fake

"The captain of the Fifth Division, Aizen Sōsuke, is dead?!" Yamamoto Genryusai Shigekuni's lowered eyelids darkened when he heard the news. Aizen Sōsuke had inherited Shinsuke Hirako's position from a century ago. His strength had been personally tested by Yamamoto, and he possessed the combat ability expected of a division captain. Yet now, just as Yamamoto had allowed the captains to handle matters themselves, Aizen Sōsuke had died? Without even causing a ripple?