Strike while he's weak; take his life.
Shen Leyou isn't sick, but he is weak.
Having just completed life's great harmony, he is now in a period of physical weakness.
Even though he too has reached the Grandmaster Realm, Tang Fei, being full against the empty, only needs a little time to cut him down.
Unfortunately, the one thing Tang Fei lacks is time.
This is why, even knowing Shen Leyou's punch was only meant to dissuade him, he still pressed forward, exchanging a knife for a punch.
It's the quickest way to solve the problem and deal with Shen Leyou.
Speaking of endurance battles...
Endurance is a good habit, but it doesn't suit Tang Fei.
Slash!
The blade pierces the chest cavity.
It makes a chilling sound as flesh is sliced open.
Blood spurts wildly.
Bang!
Tang Fei's chest is struck by a punch too.
He feels an overwhelming force crashing into him, like a flying boulder suddenly hitting his chest.
