Arc 8The Battle at Sōkyoku Hill
Duan Mu was assigned to the 9th Division as an acting captain while Ichigo and the other ryoka invaded Seireitei to rescue Rukia. When Aizen revealed his betrayal and took the Hogyoku, Duan Mu joined the fight and battled him at Sōkyoku Hill.
- Central 46 blacklisted Duan Mu and moved Rukia’s execution up to seven days away, while he suspected Tōsen Kaname had survived.
- Yamamoto assigned Duan Mu to perform the duties of the 9th Division captain, and Duan Mu took charge of its staff and unfinished work.
- Ichigo and the other ryoka entered Seireitei, and Duan Mu confronted and captured Sado when he crossed the 9th Division’s territory.
- Duan Mu learned that the ryoka were heading toward Sōkyoku Hill, but Yamamoto ordered him to remain in his district until the intruders were captured.
- Aizen revealed himself at Sōkyoku Hill, cut down Iwao, pierced Rukia, and removed the Hogyoku as Tōsen trapped Duan Mu in Enma Korogi.
- Duan Mu defeated Tōsen in his domain, sensed the danger at Sōkyoku Hill, and rushed back as Aizen gravely wounded Ichigo and fought Yoruichi and Soi Fon.
- Duan Mu surprised Aizen with a disguised kick, then joined the battle and used Flash Cry with Yoruichi’s technique to blast apart the battlefield.
- Duan Mu kept attacking Aizen by spending experience points to heal his wounds, but Aizen shattered his blade before Duan Mu restrained him with Kidō and landed a punch.