Lu Li had to go back since things were happening in the Waters Region. Together with his three wives, Lu Li teleported back to the Central Plains and then to the Demon-slaying Battleground. The three wives were asked to go back to the Prison of Wood on their own.
Inside the Demon-slaying City, Lu Li told Patriarch of Law Enforcement to send disciples of the four major families back to the Prison of Wood and asked all the patriarchs of the Demon-slaying City to evacuate.
Though Lu Li was fairly confident that he could defeat all the incoming enemies, he must tread carefully. Emperor of Heaven Reverse was cultivating recently. Staying at the Demon-slaying City wouldn't do Lu Li any good. As for Patriarch of Law Enforcement, whether he stayed or not wouldn't make a difference. Lu Li believed he could go to the Waters Region by himself.