Sosuke Aizen

A tall, stately man, handsome
Height 186 centimeters
Hair: Brown, styled in a soft, slightly tousled, "scientific" style.
Glasses: black, square-framed. It was this accessory, along with his soft, slightly drooping brown eyes, that gave him a disarming, scholarly appearance.
Clothing: Standard Shinigami uniform (shihakuso) plus captain's haori. The inside of the haori was pale turquoise.
He has a blade called Kyōka Suigetsu.
When sealed, it's a regular katana. Its main feature is the hexagonal tsuba (guard): two sides parallel to the blade are elongated, while the other four (above and below the blade) are shortened, giving the guard the appearance of a diamond or prism. The handle is wrapped in green braid.
Aizen himself often smiles kindly and appears polite and caring, but behind this lies ruthlessness and cruelty; he uses people, and if he doesn’t see any benefit, he gets rid of them.