What is aizen sousuke?

Aizen Sousuke is a fictional character and the main antagonist in the anime and manga series Bleach, created by Tite Kubo. He is a former captain of the Soul Society's 5th Division, known for his calm and collected attitude. Aizen is a master manipulator who orchestrate a complex scheme to obtain the power of a god-like being called the Hogyoku. He eventually reveals himself to be the true villain of the series and is defeated by protagonist Ichigo Kurosaki. Aizen is known for his powerful spiritual pressure, intelligence, and combat skills.