 Although Castiel learns that his stolen grace will kill him eventually, he refuses Metatron's offer to side with him, eventually convincing Gadreel to ally with him in opposing Metatron's attempt to stage a coup of Heaven even as Metatron tricks the other angels into follow him by presenting Castiel as a despot willing to destroy everything to win the war, convincing angels to 'suicide bomb' themselves and claim that Castiel told them to do it.Having gained access to Heaven's 'back door' after Gadreel sacrifices himself, Castiel defeats Metatron and throws him into Heaven's prison.Despite his defeat of Metatron and access to Heaven having been restored, Castiel continues to face challenges on a personal and large scale, as some angels prefer to remain on Earth and his stolen Grace continues to consume him.