The main villain's true form, a very evil hollow!
 
Aizen is the main villain from Bleach. He first appears as a former captain of Squad 5 of the Soul Society talking to Renji in private about his friendship with Rukia. Then he appeared with the other soul reapers noticing Ichigo and his friends breaking through the barrier surrounding the Seratei which he knew and when Ichigo and his friends were besting many soul reapers standing in their way, he faked his death waiting for Rukia to be executed so that he can take posession of the Hokyoku inside he human body. However, when Ichigo prevented Rukia from being executed, he had to get it out of her by force. After overpowering Icigo, he taunted him while escaping his arrest by the captains. Later he became leader of the arrancars and is planning to kill everyone in Ichigo's hometown for their souls in order to create a key that will give him access to the royal palace so that he can kill the spirit king. However he was defeated when Ichigo blasted him with the Final Getsugatensho, weakening him enough for Kisuke's Kido to imprison him!