Sujin Asakura

Mūshin (無有真; Literally meaning "Existence of Reality and Truth") also known as Saitō Kuchiki (斎藤朽ち木, Kuchiki Saitō) was once the head to the Kuchiki family and apprentice to the Captain-Commander of the Gotei 13 but he was soon forced to defect because they learned that he was affiliated with Konjaku Monogatarishū. He was the main antagonist for the first arc of the Part II of series and once he was defeated he left the Dark Order and joined forces with Sennō.