As the battle between Kisame and Killer B wages on, Danzō and his men continue to make an escape with Ao in pursuit. Fū is assigned to retrieve the Byakugan at all costs, and attempts to do so by casting a mind-switch style technique, but ultimately fails due to the Mizukage's interference. Kisame's attempt to capture B also fails as Samehada turns on him and the Raikage, Darui and C arrive in time to save him. The Raikage and B decapitate Kisame.
Source: Neon Alley