Ulquiorra Cifer (ウルキオラ・シファー, Urukiora Shifā; Viz Ulquiorra Schiffer)[2][1] was the Cuatro (4th) Espada in Sousuke Aizen's Arrancar army, representing the form of death of nihility (虚無, kyomu; Viz "nothingness"; also transl. as "nihilism").[3]