What sticks out most about Kenpachi is his overwhelming love of battle. His entire driving force is to fight, and while most see combat as means to an end, or a last ditch resort, Kenpachi actively seeks it out, specifically hunting for the strongest of the enemies he faces. Likewise, in a similar vein to Kurotsuchi, he often acts for his own personal satisfaction over any sense of justice. He'll obey orders given to him, but when he enters into a bout with an enemy, it's not necessarily because of duty, but because he wants to have fun - and luckily for him, the two frequently coincide.
|Kenpachi is in his element when it comes to powerful and capable opponents.|
Kenpachi is essentially a crazed beast who will hack away at his opponent. There's little finesse to his fighting style, his blade is tattered, and he hasn't even bothered to learn his zanpakutou's name. In that sense, his total sense of disconnect with a weapon that is essentially part of his soul, goes against the mantra of the other shinigami. He doesn't use fancy kido, or think out a strategy, instead he wins out with pure brute force and incredible inate spiritual pressure. That his entire attitude differs from his peers, is what makes him most fascinating to me as a character. Well, that and knowing that when he arrives with his blade drawn, you're in for a damn good fight.
Another thing that I find intriguing about Kenpachi is the juxtaposition in his character. Despite his thirst for bloody battle, Squad Eleven's captain is - in a sense - a fair and almost honorable fighter. He won't resort to dirty tricks. If you're too weak, he'll just kill you and/or leave feeling unsatisfied. If you're strong, he'll fight you in a one-on-one duel and give it his all in order to enjoy the bout. Likewise, though he's the most brutal and fierce of all the captains and while his enjoyment of combat almost borders on the sadistic, his relationship with his vice-captain, Yachiru, is a stark contrast. That he acts like big brother and protector to his tiny subordinate, accords Kenpachi a certain amount of humility. It goes to prove that he isn't all bad even though he may seem like little more than an out-of-control monster.
If I were to sum up Kenpachi, I'd say he's like a rather sizeable family dog. He growls, barks, and bites, but only when trying to assert his rank in the pecking order and test himself, or when protecting those that are threatened. However, he's loyal, especially to those he calls friend and will act as their companion and guardian. And while he may jump up and bark at those he respects (such as the way he "attacks" Ichigo), all he really wants is to play and have some fun.