The old man became increasingly nervous with every passing second.
Sam stood there unfazed no matter how many punches came at him. Of course, even if it appeared like that, he is actually in a zone where his mind is running at the highest pace possible.
The old man's technique is indeed very delicate and precise. It is very dangerous as well. It is very hard to dodge it because the old man is fast. Way too fast for any of his peers to match. And no matter how hard they tried to block these hits they are going to fail because the attacks are going to do their damage anyway.
It is one of the perfect techniques that could completely ignore the defense of an opponent.
And it is working better against the elemental attacks as Sam already noticed. All in all it is one good technique. Sam is actually tempted to learn it himself to see what he can do with it.
But he already recognized the flaws that could help him take it down.