Excavado

Excavado (Spanish for "Hollowed Out"), incorrectly referred to as a Visored, is a highly experimental and corrupting form of that was thrust upon Shigeru Yūdai. It resulted from the joint experimentation of Kagura, Bansui, and Averian, using the former's Hōgyoku and the latter's unique abilities at the conclusion of the First Spiritual War. Sometime following the Collapse it was discovered that Shigeru, believed to be the first and only example of this occurrence, was not alone. Kentaro Hiroshi's Hollowfication was also a result of Averian's power, only he did not require the Hōgyoku to facilitate the process, as Kentaro's Hollowfication took place when he was in the womb, thus making his Hollowfication natural and Shigeru's unnatural.

History
Shigeru, fighting on the side of the Soul Society during the First Spiritual War, was captured towards the end of the conflict by Averian, acting on Kagura's information. Kagura, known within the Seireitei and Rukongai as the Illusive Man, had secretly been feeding Averian information regarding the state of the Gotei 13, hatching a plan to use one of their most skilled operatives, Shigeru, against his own people. Bansui offered the solution by introducing a new form of Hollowfication he had been working on in secret, which not only eroded the boundary between and  without the ill-effects of Soul Suicide, but also eroded the target's mind to make them more susceptible to control.

Although his effort was spirited, Shigeru was no-match for Averian's premier Battle Doll, and was quickly defeated and captured and taken to.

Within Bansui's secret base beneath the sandy plains Shigeru was subjected to a series of experiments, the experimental form of Hollowfication only the first of many, and was also drugged to erode his will to fight back as well. Thankfully Shigeru's will had always been solid and any attempts to erode his mind was met with constant failure, leading Bansui to grow impatient. He cut corners in the hopes of breaking Shigeru, but ultimately failed, his impatience leaving his vision clouded. Seizing upon a mishap that broke his restraints and utilizing his drug-enhanced spiritual power, Shigeru escaped, drawing the attention of Kenji Hiroshi who had been in Hueco Mundo looking for his friend. The two escaped but Shigeru's state was irreversible. He opted to go into self-imposed exile after the Gotei 13 and Central 46 attempted to arrest him, fighting his way past Captains Shin Nagakura and Tadashi Kori. In the he absorbed the powers of countless spiritually aware s to bolster his powers, eventually gaining enough power to stave off the attempted arrests of the Gotei 13, fighting against and defeating Ryōta Hachirō.

Shigeru set himself up in Horiwari where he learned to harness his new-found powers. He would eventually become the godfather of Kentaro Hiroshi, being responsible for training the latter to control his own Hollow powers, which where later discovered to be identical to those wielded by Shigeru himself.

Powers

 * Acidic touch: Shigeru, shortly after awakening to these powers immediately prior to his escape from Bansui's lab, was capable of breaking through his restraints by seemingly burning them away in a drug-induced trance. He later showed he was fit to control this power, at times applying this "acid" through physical contact, often from multiple parts of his body at once.


 * Acidic spit: A lesser-used variant of the primary power, which allows Shigeru to mix "acid" into his spit at will. He used it against Shinzō after the old Imawashī bound his arms, burning the latter's eye to the point he was blinded.


 * : An ability that allows Shigeru to regenerate lost limbs and almost instantaneously heal injuries he has sustained, the sole exception being organ damage or decapitation. He was seemingly fit to "turn off" this power. During his final battle with Kentaro (in which Shigeru was attempting to hold off Shinzō's control), Kentaro stabbed him through the stomach and slashed him deeply across the chest, all without activation of Shigeru's high-speed regeneration, implying Shigeru was actively blocking the technique from activating so Kentaro could kill him and Shinzō both.


 * Soul-Body Separation: An ability that allowed Shigeru to forcibly extract a soul from a living body and place said soul in another object, usually a specially made.


 * Soul devouring: An off-shot of the primary power that enables Shigeru to forcibly absorb, dominate, and then utilize the reiryoku comprising the devoured spirit indefinitely; sometimes picking up weaker variants of any unique ability said soul possessed. He was known to use this power without reservation immediately following his exile to quickly gain power to stave off the numerous attempts to arrest him by the Gotei 13. He absorbed so many souls in so short a time he was capable of fighting Ryōta Hachirō to a stalemate for the majority of their battle, eventually overpowering the experienced ex-Captain. After joining the Imawashī however he rarely, if at all, used this power, relying upon other means to grow stronger.


 * : Upon his Hollowfication Shigeru gained access to this usually -specific release through his Zanpakutō (which was speculated to have undergone Hollowfication alongside his master), which was due to Bansui's Hollowfication being far more corrupting and experimental than the version applied to the Visored many years prior. Using it Shigeru assumed a Hollow-like form, gaining an assortment of new abilities usually reserved for the Arrancar, including, the quick-firing , and the signature attack of the Hollow race. He was also fit to advance the standard Resurrección to the next level, referred to as Resurrección: Segunda Etapa, which tapped his Hollow powers to their limits. Like the usual Resurrección, this second state further transformed Shigeru's body, as well as enhancing his already formidable powers.


 * Hekigenkai: A term coined by Kenji and a form utilized by Kentaro, which is essentially identical to Resurrección. He later developed a second-stage identical to Resurrección: Segunda Etapa, which was referred to as Hekigenkai: Second Stage.


 * : A form of high-speed movement first utilized by the Arrancar, which Shigeru never demonstrated himself. Kentaro, perhaps due to his status as a "natural" Excavado, utilized this form of movement without reservation as a younger man, to the point it was identified as his trademark. His speed was such that he could easily surpass the speed reached by Captain-class combatants.

Behind the Scenes

 * The powers of an Excavado are more focused on basic Hollow skills than those shown by Arrancar, as they have not shown the ability to use Bala attacks, nor do they have access to Hierro.