Honestly, the only real reason I see playing him is the opponent has less options for the free hit after being parried because he gets pushed back so much. You can't do a "normal" BNB of guard break into heavy.
His gameplan from when I used him, and saw other competent people play him, seems 100% based around parries and baiting, which every other character in the game can do too, while also having other tools available. His mixup into unblockable or canceled into side light is pointless when the opponent has some open space, because you can back dash into back roll to avoid the whole situation. I even tried to do unblockable finisher into feint, to forward dash grab and it seems like the back roll is guard break immune for some reason. I suppose you could maybe do unblockable finisher feint into forward dash light, but that is a ton of stamina and a hard read for something that would lose to the opponent doing literally anything else
Also, apparently in the beta, Kensei side dash light attack was punishable on block (not parry) with a free inescapable guard break. Not sure if that's still the case but if so...that makes it even less viable for "randomly" trying it. It's viable to parry it on reaction but having it punishable on block gives no risk.