He was not in the Returning Core Realm at that time, incapable of controlling his own fate. He himself struggled on the Immortal Path, so how could he have the spare energy to help others.
Now, he had reached the Returning Core Realm. He had the ability to control a part of his own destiny. When he met Song Miyao, he questioned his heart and found that while he was indeed unfeeling, he couldn't sever his emotions for Zhao Yunniang.
The choices he made at different times would vary due to various circumstances.
Although bringing Zhao Yunniang onto the Immortal Path now still posed more harm than good, Xu Xing felt that if he didn't, he might regret it for the rest of his life.
Even if... Zhao Yunniang's aptitude was insufficient, and she perished midway on her pursuit of immortality, it was still better than him doing nothing.
"I am your husband..."
"You... don't need to treat me like a stranger."
