Aizen is a soft-spoken intellectual, accented by glasses during his time as a shinigami captain. While he appears to be very kind to his subordinates, he cares very little for them in truth. According to Aizen himself, he is not bound by morals and will therefore stop at nothing to further his ambitions, including manipulating or killing anyone if he deems it necessary.Aizen is an extremely potent combatant, well above most captain-level shinigami. While the full extent of his power remains unclear, he implies that he has reached the limit of his shinigami power in all four forms of shinigami combat: swordsmanship, hand-to-hand combat, footwork, and kidō. He goes on to state that the only way for him to advance beyond that would be to gain and master hollow powers. His mastery of the regular skills are such that he is able to stop released zanpakutō, including Ichigo Kurosaki's bankai, with one finger, and he can near-effortlessly defeat several captain-level opponents at once.

http://en.wikipedia.org/wiki/Himura_Kenshin
Hiten Mitsurugi-Ryū - utilizing godlike speed and precision to deal powerful blows that usually bring down foes with one shot.
Battōjutsu - Art of Drawing the Blade

Физически абсурдно е да се изредят всичките техники, които Кеншин може да прилага, по-добре вижте листа във вики.

....не виждам как тоя сменик ше го бие

Срещу илюзията на Айзен Кеншин не може да направи нищо
Тъжно, но факт