Aizen

Sōsuke Aizen served as the 5th Division's previous captain for the Gotei 13. Later, he departs Soul Society alongside Gin Ichimaru and Kaname Tsen, two of his supporters. The man's aide was Momo Hinamori. He formerly held the position of lieutenant for Shinji Hirako's Fifth Division.

Aizen attacked Soul Society with an army of Arrancar. However, he was finally defeated by Ichigo Kurosaki, sealed away by Kisuke Urahara, and imprisoned for his crimes. He is also one of the greatest anime strategists of all time.

Aizen prepared an attack on the Soul Society and used both Hollow and Shinigami to acquire the supremacy he believed was his right. Aizen possesses unimaginable experience and unmatched strategic and controlling skills. He is also extremely strong and immortal.

Without even lifting a finger, Sosuke Aizen caused chaos and divided everyone. Because of his plot-breaking omniscience, fans are persuaded that Aizen is a scary mastermind who can read people like a book.

By the time he escapes Muken, he has returned to his former laid-back attitude. He also disregarded Shunsui Kyraku's compliments on his current abilities and even showed some symptoms of having a change of heart by deciding to fight Yhwach. He rejects Yhwach's proposal to unite the three planes of existence to remove the fear of dying. He believes that in Yhwach's universe, no one would ever have the courage to face such a danger.

Anime: Bleach

Watch here: https://www.crunchyroll.com/series/G63VGG2NY/bleach