Sōsuke Aizen is a prominent character from the anime and manga series Bleach by Tite Kubo. Initially introduced as the calm and kind-hearted captain of the 5th Division in the Gotei 13, Aizen is later revealed to be a cunning and ambitious villain. He orchestrates a grand plan to overthrow the Soul Society, fueled by his desire to attain godlike power and control over all realms. Known for his immense spiritual pressure, mastery of the Zanpakutō Kyōka Suigetsu (which manipulates perception), and strategic genius, Aizen is one of the most formidable antagonists in the series. His iconic betrayal and complex personality make him a standout character in anime history.