Aaroniero Arruruerie

Aaroniero Arruruerie was a gillian, the weakest class of menos, before becoming an arrancar, and the last of the first-generation Espada. He usually covers his face with a white mask covered in holes while in the light. In place of a normal head, he has a large, glass capsule filled with red liquid and two floating heads. The two heads are both tattooed with the number 9 and tend to talk in tandem when revealed, giving the effect of two people speaking in turn. The upper head speaks with a deep voice while the other speaks in a high-pitched, child-like voice.

While all hollows can cannibalize each other to gain power, Aaroniero has the ability to completely absorb other hollows, merging not only their extra power with his own but also gaining their individual abilities. Once a hollow is absorbed in this fashion, Aaroniero can manifest any aspect of them at will, including their physical form. It is for this reason that Aaroniero, despite his gillian status, was able to become an Espada. Through an unusual series of events, he also absorbs the shinigami abilities of Kaien Shiba by eating Metastacia. The weakness of this power is sunlight, which nullifies it on contact and reveals Aaroniero's true form. Aaroniero also has the ability to broadcast information of whatever he is currently seeing or experiencing to other arrancar, which he does prior to his death at the hands of Rukia Kuchiki.

Aaroniero's zanpakutō is 'Glotonería' 喰虚（グロトネリア）Spanish for "gluttony," Japanese for "eating hollow". It is activated by the command "devour" 喰い尽くせ kuitsukuse. When sealed, it takes the form of a deformed arm-like appendage with many sprouting tentacles that is concealed under a glove. It allows Aaroniero to manifest any power he has absorbed through his zanpakutō, morphing it into a perfect approximation of the one he absorbed, as he does with Kaien's Nejibana. His absorption ability also allows him to perfectly mimic the accompanying battle styles of those powers. When released, it turns Aaroniero's lower body into a huge, blob-like mass resembling an incredibly bloated cartoonish octopus, with dozens of stubby tentacles and mouth like mask pieces, giving him access to the full range of his absorbed abilities. He can still manifest the powers of those he has absorbed in this form, but has no limit to the total number.