Quickstep: A Kenpachi can charge as a swift action without provoking any attacks of opportunity.
Poof you instantly appear next to your target and hit that shit with your full attack. It's pounce with panache dammit, you can add flavor text such that you seem to disappear while in transit. All that matters is you are in position A, you move to position B so fast that nobody can do anything about it. The rest is fluff.
If you don't want it just as a charge for attacking, then change it so you can move twice your movement speed as a swift action without drawing an AoO. That way you can dart around, or just run faster in addition to being able to Quickstep up for your full attacks.