Ukitake shook his head. “I don’t know. When we die in Soul Society, our souls should eventually move on to the world of the living and begin a new existence there. Hollows complicate matters. They interrupt the cycle of life and death by consuming souls and threatening the balance. Perhaps he was truly released that night, or perhaps when Kuchiki defeated the Hollow again in Heuco Mundo.”
“Or perhaps I linger,” Kaien’s specter said. “Perhaps my soul can find no peace.” His captain’s face drained of color at the words, and Ukitake abruptly took the seat nearest to hand, breath catching in his throat, another attack of illness threatening.