The Arrancar Arc is a significant storyline in the anime and manga series Bleach, created by Tite Kubo. This arc follows the events of the Soul Society Arc and introduces the Arrancars, powerful beings who are former Hollows that have gained Shinigami-like abilities. The main antagonist of this arc is Sōsuke Aizen, who seeks to create an army of Arrancars to challenge the Soul Society. During the Arrancar Arc, the protagonist Ichigo Kurosaki and his friends face off against various Arrancars, including notable characters like Ulquiorra Cifer and Grimmjow Jaegerjaquez. The arc explores themes of power, identity, and the struggle between good and evil, as Ichigo and his allies work to protect their world from Aizen's plans.