I will probably have to agree with you ; so far two fights with Kana, two freezes. Basic attacks just leave the game trying to do something but not succeeding in doing it, and even if I click "end turn" it stays stuck on "Waiting"
Addendum after playing around : it seems that Kana freezes combat a lot less when I don't sneak. Seems to be some sort of interaction between Kana's abilities/behavior and getting out of sneak during combat on his turn.