Lift the Limit

Shawlong shears off the right wing of Hitsugaya's Bankai with his Tijereta claws, only to watch the captain rebuild it from the moisture in the air, and he admits admiration for a captain who holds his ground while hopelessly outmatched. When Hitsugaya wonders whether being Arrancar number eleven makes Shawlong the eleventh-strongest, the Arrancar corrects him: for those numbered above ten, the figure marks birth order rather than power. He explains that Hollows remade into Arrancar by the Hogyoku are counted in the order of their birth, but the ten mightiest are ranked one through ten by their spiritual power, forming the Espada who command the rest and bear their numbers somewhere on their bodies. He warns that one of tonight's group is the sixth Espada, Grimmjow.

Grimmjow catches the blade of Ichigo's Zangetsu barehanded and flicks him into the sky, reminding him he did not come to slaughter helpless prey and is holding back, then goads him to release his Bankai or end up riddled with holes like Rukia. Ichigo obliges, to Grimmjow's delight. Wounded again, Hitsugaya silently begs Rangiku to hurry, and her communicator relays that Gentei Kaijo has been approved. She casually stops a stomp from Nakeem with her wrist, thanks the institute, and passes the word to Hitsugaya and Renji. The three bare the division crests on their chests and invoke Gentei Kaijo, sending towering columns of spiritual pressure roaring into the sky.

From Volume 24, IMMANENT GOD BLUES, in the Arrancar arc, and adapted into Episode 120, Hitsugaya Scatters! The Broken Hyorinmaru. This chapter introduces the concept of the ten Espada and Grimmjow's rank as the Sexta, and sets up the limiter release, Gentei Kaijo, that turns the tide of the Karakura fights.