Baraggan Louisenbairn (バラガン・ルイゼンバーン, Baragan Ruizenbān?, romanized as Barragan Louisenbairn in the Japanese media) is the Segunda Espada. His name is believed to reference Mexican architect Luis Barragan. Before becoming an Espada, Barragan reigned over Hueco Mundo from Las Noches and considered himself the "god of Hueco Mundo". Aizen, before he defected from the Soul Society, offered Baraggan greater power if he submits to him. Though he refused the offer, Baraggan is forced to accept after Aizen easily killed many of his followers, intending to someday kill the Soul Reaper with the very power he gained from him.
Baraggan is the oldest of the Arrancars, the remnants of his mask taking the form of a five-pointed crown and his Hollow hole is located in the center of his chest. He bears large visible scars on the left side of his chin and across his right eye, and wears a large rope-like sash with a sun-crested buckler attached to it in addition to the regular obi sash. Though dethroned, Baraggan still sees himself to be superior to every form of life. Though given the position of Segundo Espada by Aizen, Baraggan asserts his leadership once Aizen is trapped, giving orders from a skull-adorned throne, even instructing Halibel to "not underestimate him". As an Espada, Baraggan's representation of death is Senescence, stating it to be absolute as he is able to slow down his opponent's close range attacks and even dissolve his enemy's bones by simply touching them. To protect himself from his own power, Baraggan devised an external immunity to his aging abilities.
His Zanpakutō is Arrogante (髑髏大帝（アロガンテ）, Arogante?, Spanish for "Arrogant," kanji translates as "Great Skull Emperor") and it takes the form of a giant battle-axe. When released, Baraggan transforms into his normal Hollow form, a crowned lich. In this form, Baraggan's aging powers are intensified so that even a step he takes causes an entire area to rot. He can perform Respira (死の息吹（レスピラ）, Resupira?, Spanish for "breathe", kanji translates as "Breath of Death"), a mist that continually ages whatever it touches, reducing the person to dust or forcing that person to sever the inflicted body part in order to escape the decaying process. Baraggan's Respira also has the power to deteriorate kidō, as demonstrated when he dissolves one of Hachigen's barriers. He has gain the use of his original Hollow form's weapon Gran Caída (滅亡の斧（グラン･カイダ）, Guran Kaida?, Spanish for "Great Fall," kanji translates as "Downfallen Axe").
After all of his Fracciones are killed, Baraggan engages Soi Fon and Ōmaeda before taking on his Resurrección form. From there, Barragan maintains the upper hand, as he manages to force Soi Fon to amputate her right arm with his Respira and then detoriates her Bankai before it can hit him. However, the Visords intervene and Hachigen joins the fight, creating multiple kidō barriers to box Baraggan in so Soi Fon's Bankai can make a direct hit that most shattered Barragan's skull. Furious of the inflicted injury, Baraggan releases his Respira everywhere, eventually hitting Hachigen's right forearm. However, in a gambit, Hachigen uses his kidō to sever his infected forearm and teleport it inside Baraggan's unprotected stomach. Literally dissolving from the inside and refusing to die alone, Baraggan makes an unsuccessful attempt to kill Aizen with only his crown remaining before it shattered.
He is voiced by Shōzō Iizuka in Japanese version and Steve Kramer in the Hueco Mundo arc (though Michael McConnohie voiced Baraggan in the Fake Karakura Town arc).
Read more about this topic: List Of Hollows In Bleach, Arrancar, Espada