I would say kin generally need a slight tone down. Something like making flinch once per activation.
I don't think they are as, arguably, overpowered as some key words (cough colette, yan lo, dreamer) but I think they are enough ahead of the curve to require a slight balancing.
There's currently a lot of negativity around the kin from a few very vocal members of the UK meta. While I disagree that they are broken, as some have suggested, I do think they are a little too good.