Bleach: Season 1, Episode 130

1 - 130: The Invisible Enemy! Hitsugaya's Merciless Decision

Hitsugaya finds a discovery that helps them in the battle aganist the Arrancar they are battling that it can shapeshift into other souls. And they find out Yui is a clone of the Arrancar. Hitsugaya and group are trying to protect Shōta and figure out a plan to beat the Arrancar.