The reason Ye Chen headed to the trading palace was not only because he wanted to disguise the true purpose of his trip, but he was actually looking for a Fist Art manual.
During the fight against the ghost head, his Star Scar Sword was bitten and controlled by his opponent. He, who was bare-handed, had no way of escaping the situation. If it were not for that Tornado Broken Clouds Art which was performed by his legs at that critical moment, he would have already been another dead soul under the ghost head’s claws. If he had trained a powerful fist art, then maybe he could kill the ghost head with one punch, or at least badly wound him and allow himself to escape that trap.