Second move of Hueco Mundo! Hitsugaya vs Yammy

Deep in Las Noches, Aizen employs the Hōgyoku to finish transforming the heavily mummified Wonderweiss Margela into an Arrancar, then grants Ulquiorra leave to lead a raid on Karakura Town. Aizen also hints at a hidden truth of the Hōgyoku that not even Urahara ever uncovered.

In the Human World, Ichigo trains with the Visored but can hold his Hollow mask for barely ten seconds. In the Seireitei, Ukitake watches Rukia and Orihime spar as they steel themselves for the coming war, while Yumichika fails to commune with his prideful Zanpakutō. A Garganta then tears open above Karakura, delivering Yammy, Luppi, Grimmjow, and the vacant-eyed Wonderweiss.

Grimmjow breaks away to hunt Ichigo, and Yammy drops down to fight Hitsugaya, who greets him with a flurry of ice. Luppi confronts Ikkaku and Yumichika as the Research Institute detects Espada-class Reiatsu. Freed from Visored restraint by Shinji, Ichigo meets Grimmjow, activates Tensa Zangetsu, and prepares to Hollowfy, while Urahara resolves to enter the fray in place of the exhausted Renji and Sado.

Aizen creates the Arrancar Wonderweiss Margela using the Hōgyoku and dispatches the Espada to invade Karakura Town. Hitsugaya engages Yammy, and Luppi reveals himself as the new sixth Espada against Ikkaku and Yumichika. Ichigo leaves his Visored training to confront Grimmjow and prepares his Hollow mask, and Urahara decides to join the battle.

The 138th episode adapts chapters 229 through 231 in the Arrancar arc. Its Kon-sama guide segment shows an overexcited Hisagi determined to cover the Espada invasion for the Seireitei Communication. The anime added Rukia and Orihime's training flashback, with Sentarō and Kiyone bickering, plus Ichigo verbally invoking his Bankai against Grimmjow.