Bleach: Season 13, Episode 251
The 3 elites are gloating over their success when Kōga and Muramasa appear. Kōga kills them, and Ginrei is informed. Muramasa talks to Kōga to try and help him over his anger, but they are found by Ginrei. He inform Kōga the likely sentence for killing the Elites is execution, and Kōga goes insane. Muramasa tries to possess Ginrei’s Zanpakutō, but phases through Ginrei. Kōga removes his hairpiece, and departs. He then goes on a killing spree. Muramasa tries to reason with him but fails, lamenting that he can’t hear Kōga anymore. Yamamoto is informed of what’s going on, and Ginrei tells them how to resist Muramasa’s power, and Yamamoto volunteers to help. Kōga rants at Muramasa and threatens him. He meets Ginrei and Yamamoto for a showdown. He tries to use Muramasa on them, but he won’t release. They use this opportunity to arm with the spears used to seal Kōga’s coffin. These immobilise his limbs, allowing Yamamoto to use Kidō to imprison him. Back in the present, Kōga thinks Muramasa betrayed him, but Muramasa claims he never heard him. Kōga removes his blade from Muramasa, and tries to kill him, but Byakuya blocks the blow and challenges him.