Zangetsu, the spirit of Ichigo's zanpakutō, brings Ichigo into his world. Through fighting a hollow version of himself, Ichigo realizes that zanpakutō are more than mere tools, and that simply knowing name of his zanpakutō does not make him more powerful. Ichigo is then able to fight Kenpachi on equal footing, and as the two clash in a massive strike, Ichigo collapses.