Sang Que couldn't see, indicating that Wu Renxing, this Gambling Ghost, indeed had reached the Ghost Level. When he doesn't voluntarily show up to kill, people of insufficient level can't perceive the existence of the Gambling Ghost.
The Taoist Sect has the Eye-opening Talisman, but it can only let ordinary people see Evil Level existences.
The Deceit Dynasty has many methods and items to deal with Evil Level existences, but once reaching Ghost Level, all aspects seem weak and lack power.
Yuan Gui is an ordinary person and can see Wu Renxing. This is not surprising, as Yuan Gui is causally connected with Wu Renxing turning into a Gambling Ghost, and it was Yuan Gui who personally handled Wu Renxing's corpse.
The lantern hanging over the entrance of the gambling house is a soul lamp, a regular item used by the Evil Suppression Bureau with many purposes.
