The Wengquan Villa indeed harbored many monsters, of course, these monsters were merely the Blood Race.
Yusuf Zuck had brought back ten in one go last time, with Miles O'Brien following one, Paisley Kirk following another, Ariel Higgins following another, and one left in the manor to guard the place; thus, in total, the monstrous aura emitted by the four mighty Blood Races was instantly captured by the three great experts.
Vampires are also monsters, and the slogan of the three great experts was to slay monsters and eliminate demons, or to protect the way by exorcising demons; hence, not having found Yusuf Zuck, they decided to slay the monsters first.
