 There are also hollows with Soul Reaper (a death-related entity)-like characteristics called .One of the series' main storylines has Sōsuke Aizen (the primary antagonist for the majority of the series) and his arrancar (particularly the ten Espadas, the strongest ones) as the force opposing the protagonists.The creator of the series, Tite Kubo, used many Spanish motifs for the series' hollow-related elements.