Many intriguing villains populate the story of Bleach and that includes the 10 Espadas -- the elite Arrancars under Sosuke Aizen's command. Their appearances and abilities vary widely, from brute-force fighters like Grimmjow to science-types, such as Szayelaporro Grantz or the assassin-like Ulquiorra Schiffer. But what about Aaroniero Arurruerie?
It's true that Aaroniero is among the weakest of the Espadas, and he only had one major fight scene in the main story of Bleach. But still, that was enough time to see just how bizarre this villain is, and that includes his methods, his skills and, weirdest of all, his anatomy. Let's review his case.
Aaroniero Is Made Of Thousands Of Hollows
It is clear in Bleach lore that ordinary Hollows can become much more. Cannibalistic ones can feed upon each other and meld together to form Menos Grandes, and such Hollows can continue to eat their own kind to become even stronger, evolving into Adjuchas class Menos or even the dreaded Vasto Lorde class. Barragan Luisenbarn and Tier Halibel are Vasto Lordes who evolved that way, but Aaroniero tried something different.
He is still a Gillian, unusual among the Espadas, but he ate so many other Hollows that he became as strong as an Adjuchas anyway. His power is called "Glotoneria," and he told Rukia that he has eaten 33,650 Hollows and amassed their power inside him, without evolving into an Adjuchas. This is because he represents the sin of gluttony.
Aaroniero Can Look Like A Soul Reaper
No, Kaien isn't a true Soul Reaper; no Hollow can become a real Soul Reaper, even if they remove their skull masks and gain zanpakuto and a human form. But Aaroniero got closer to mimicking a Soul Reaper than anyone else did, and it's all thanks to his Glotoneria power.
Kaien Shiba was a beloved Soul Reaper who got possessed by Aizen's experimental Hollow, Metastacia, and their bodies fused. Rukia was forced to kill Kaien and allow him to live on in her heart while Aaroniero found and ate Metastacia. Therefore, he added Kaien's spiritual body and powers to his own, making Aaroniero the lone Arrancar who can perform a shikai. That shikai is Nejibana, taking the form of a trident that is used in flowing, elegant movements during combat.
Does Aaroniero Have One Mind... Or Two?
When Rukia met Aaroniero, she was shocked to see Kaien Shiba's face staring right back at her. But something seemed very wrong about this, and Rukia was convinced that something was afoot. She was right: Aaroniero's true form looked nothing like Kaien or anything she'd ever seen before.
Aaroniero has two spherical heads floating in a flask and in this form, Aaroniero says "us" and "we" instead of "me" (as he did in his Kaien disguise). Does Aaroniero do this to fit the fact that he has two heads? Or is he truly two personalities in one, who can actually talk to each other? It's not entirely clear.
Aaroniero Is On Permanent Life Support
Aaroniero has two heads, and it seems that neither of them can breathe in the open air. When Rukia saw Aaroniero's real heads, they were encased in a tall glass flask, suspended in a mysterious red liquid (in fact, not even Szayelappro knows what it is).
Rukia wasn't sure if that liquid was part of Aaroniero's body or something that was given to him later, but in any case, Aaroniero relies heavily on it, like a fish in water. When Rukia stabbed Aaroniero's head and shattered the flask, Aaroniero's read heads were exposed to plain air, and they both suffocated and died. One of them panicked and cried out to Aizen for help, while the other muttered a curse and crumbled away.
Aaroniero Possesses Sense Sharing
Rukia never saw this in action, but Aaroniero has another ability: ninshiki doki. This is the ability to share sensory data, according to Ulquiorra, and it's Aaronerio's duty to relay his experiences to his allies (probably so they can coordinate better on the battlefield).
The entire time Aaroniero was fighting Rukia, he was transmitting that information to the other nine Espadas, and that was how they knew when he died at Rukia's hands. In particular, Ulquiorra used this data to taunt Ichigo, claiming that Rukia and Aaroniero had killed each other. Otherwise, he couldn't have known.