Those Outer Realm Beings seem to hold an inexplicable fear of the daytime!
So, having entered Sin City for so many years, they've always dwelled within the underground castle... Now, with so many Martial Arts Experts entering the underground castle during the daytime, what if they discover the Outer Realm Beings? What then?
Others may not know, but Wang Lan is aware that although the Outer Realm Beings fear the daytime, it's not a lethal vulnerability… Even if they were exposed to the sunlight, they still possess sufficient strength to kill any troublemakers.
During Wang Lan's tenure controlling Sin City, a few years back, several major families were greatly dissatisfied with the Outer Realm Beings' secret control over Sin City, hence they covertly planned a rebellion, intending to strike at the Outer Realm Beings during the daytime and slaughter them all.
The outcome was very clear; all families that took part in the uprising were easily dispatched by the Outer Realm Beings.