Giant Hollow Fortress

This was the Giant Hollow Fortress commanded by the Unnamed Female Arrancar, in an attempt to attack Karakura Town. Its core was the most powerful part, as well as the most fragile,

Summary
This fortress was later destroyed by Urahara Kisuke's Benihime, after the Karakura-Raizer Team prevented it from destroying Karakura Town, although it wasn't much threat.

This Fortress is made up of hundreds of Hollows, merged together, and creating a giant Hollow-like Building.

As it was destroyed by Urahara even before it could attack, the full extent of its powers remain unknown. It is believed that the Female Arrancar was either blasted away together with the explosion of the Fortress, or killed before it exploded by Karakura-Raizer Erotic, with her special attack: Hyper-Erotic Mode.