When Duanmu Huai walked out of the Royal City, a large crowd of people followed him.
These people were, of course, the humans "raised" by vampires in this city, mostly young ones—naturally, vampires probably don't enjoy drinking the blood of elderly people, and as for the older humans... well, in a city where vampires hold the power of life and death over humans, there aren't many who live to old age.
Of course, Duanmu Huai did not need to lead these people through the dim tunnels again and into Twilight City. Because when they came out, the Night Guards had already cleared the paths and joined Duanmu Huai and the others. As for dealing with the vampires, Duanmu Huai entrusted that task to the Night Guards.