Dark History! The Worst Shinigami Is Born

The flashback continues and reveals that Kouga killed the people who had framed him, but after Ginrei confronted him, he went insane and began killing anyone he perceived as an enemy. Muramasa tried to reach out to Kouga but eventually was no longer able to hear his voice. Kouga was finally defeated and sealed away by Ginrei and Yamamoto when Kouga's call for Muramasa went unheard. In the present, Muramasa asks why Kouga stabbed him, as he had worked hard to bring about his return, but Kouga responds that zanpakutou are tools that obey their masters' commands. He tries to finish off Muramasa, but Byakuya steps in, saying that he is no longer worthy to be called a Soul Reaper.