Su Yongzhen dragged Xiang Yu to the hotel, then just left him there and walked away. He didn't know why he saved Xiang Yu, maybe it was just a spur-of-the-moment thought.
He was an assassin, and he had been keeping an eye on Xiang Yu for a while. It wasn't a coincidence that he encountered him there today. When Xiang Yu sneaked into the villa, he already knew and had been lurking in the shadows.
He had been waiting outside for two days until he heard shots fired inside. Then, he circled around the villa a few times and happened to see Xiang Yu being chased.
Luckily, he arrived just in time. If he had been a few minutes later, Xiang Yu would probably have been beaten to death.
Su Yongzhen knew he had committed a grave sin for an assassin, but he just couldn't bring himself to kill Xiang Yu.
He left Xiang Yu by the door of the hotel. Upon seeing a security guard approaching, he then drove away.
