[Sarinpa1]

Aside from free movement in an attack, heaven kick is already useless as it is. Quaking was the only reason to use it aside from that. And the damage isn't that good either.

I don't agree with knockback. Other skills have that...and do it better. Because I don't see why one wouldn't simply move beside the person and use dragon gale.
And no, it is rare to lack ki.

If it really gets touched (With which I disagree) I suggest the knockdown is not guaranteed. Using stats, rank of the skill, or something to calc it.