Now that I think about it, Ma Kensei may be the second strongest Ryo master. From what I can remember he's a master of all Chinese martial arts. If that's the case that means a couple of things:
1. He's a mixed martial artist.
2. He's mastered over 300 martial arts.
3. The number of techniques he mastered is likely second only to the Elder.
He likely has a technique for almost any situation.
I'm certain that Ma is a lot stronger than he appears. Not quite legendary yet, but probably the closest, a bit closer than Akisame.
We can see that in the "master missiles" scene. Hayato can make a 90 degree turn in mid air, and can propel himself in perfect straight lines like a bullet. All the other masters made jumps that look like an arc...
but Ma's "arc" is almost a 90 degree turn too. It shows that at least in sheer mastery of techniques, he is the best at Ryozanpaku other than the Elder.
Another clue is that Ma had never, ever gotten serious, in a way just like the Elder. Even against Mikumo, his aim was only to take her clothes, much more difficult than landing a hit to hurt, because you have to be that much more delicate with your motion.