The reason why he left the Tianjin Palace was because He Guangshen's qualifications were always low and he could not break through to the Ancestral God Realm. Therefore, he simply left the Tianjin Palace and went to the Xiyao Realm to establish Jiuwei City.
He relied on the alchemy he learned in the Tianjin Palace to concentrate on managing Jiuwei City, and slowly built this Jiuwei City into the largest trading base for Yuancao Ling Yuandan in the entire Xiyao Realm and even the entire Five God Realm.