Ah, yes, I'm not denying the probability of the renegade shinigami vs Kenpachi fight. Seeing how much that dude hates Kenpachi, it's probably the most likely fight of them all. But based on his fight back at the mansion so many episode ago, I don't just see how he could have any chances agaisnt good old Zaraki. Of course he could still hide some trump cards, even bankai, but so far it has been somewhat unimpressive. The headphones, however, has fought pretty hard.

Well, I'm sure they have thought hard who to put against who, so good enough fights should be waiting in the future.