Kurotsuchi Mayuri

Kurotsuchi Mayuri is the captain of the 12th Division of the Gotei 13 and the second president of the Shinigami Research and Development Institute. A mad scientist for whom the whole world is a laboratory and living beings are merely expendable material. His genius is comparable to Kisuke Urahara's, but unlike the latter, Mayuri does not recognize moral restrictions in science. He is cold-blooded, sadistic, and takes pleasure in the suffering of his test subjects. His zanpakutō, Ashisogi Jizō, in shikai paralyzes the victim while leaving them the sense of pain, and his bankai, Konjiki Ashisogi Jizō, releases a deadly poison. Mayuri modifies his own body without hesitation, invents new drugs, and resurrects Arrancars as obedient puppets. He despises perfection, believing that it leads only to despair. Behind his outward cruelty hides an obsession with creating life and a dream to surpass Kisuke Urahara. After Nemu's death, he created Nemuri Hachigo, his new daughter-creation, and continues to serve the Soul Society, remaining one of the most dangerous and unpredictable captains.