Ulquiorra Cifer is a male Arrancar that was once an Anása-class Hollow. the former fourth Espada in Sōsuke Aizen's army of Arrancar. He met his end after being defeated by Ichigo Kurosaki in the latter's Hollow transformation. It is later revealed that through an obscure method, Ulquiorra resumed his life as a Hollow and eventually regained his status as a natural Arrancar. He was recruited by Kurama Kawahiru to become a member of the Quasso Regios.