Can someone explain to me how Asuma's mystery skill works? It looks very interesting and Im having trouble utilizing it.

So far, what i assumed is that if yo have over 70 chakra BEFORE using the skill, the skill will have no cost and will immediately be reset?

but that doesnt seem to be the case. I would greatly appreciate it if someone can explain to me how Asuma works.

So how does "Flying Swallow" work?
also interested in his passive "Chakra Blade" (is this just more chakra = higher chance of triple taijutsu attack with Repulse?)