Captain of the 11th Squad in Bleach. One badass mother fucker. Completely blows away the fact that Bankai makes you a strong shinigami. His reastu level is so large that it weighs down people so much it seems like the reastu it self has the intent to kill. His Zanpakuto is unnamed and is in Shikai state, and cannot go to normal state, like Ichigo. Unlike any other Captain, Kenpachi can not go Bankai. He is backed up by his Eyepatch and insane strength and endurance. Kenpachi only fights with one hand, but he has been shown fighting with 2 using a special technique called Kendo which Annihilated the 5th Espada Nnoitra very fast.
His Eyepatch holds back his intense reatsu, and when he takes it off, he explodes with power. It was shown that just the reatsu coming from him cut down a building. Kenpachi has always been insanely strong, beating Ikkaku when he was still a trainee in Rukangai. His Vice-Captain, Yachiru, seems incredibly attached to Kenpachi since he trained her from childhood. She always tells people not to bother her or Kenpachi when Kenpachi is fighting.
Kenpachi is so intensely in to fighting, he has been described as a "Demon" by Tousen. Kenpachi took out both Tousen and Komomaru, even while Tousen's Bankai kills all your senses, Kenpachi still managed to beat Tousen.
Did you see what Kenpachi did to Nnoitra in Bleach 197? Poor guy...