Sun Hang didn't go to track that guy... It's not that he lacked "alertness," as the other person claimed, but rather that he didn't feel any threat from him at all.
This ability to turn one's body into a phantom seems magical, but Sun Hang could tell that it had many limitations and wasn't very powerful in combat... The key point was that although his body became phantom-like, the Hunter in this state didn't seem to be immune to all forms of physical attacks like Spiritual Body Type Mysterious Creatures.
Otherwise, the guy wouldn't have rushed back to his room so quickly after being exposed.
The greatest benefit of this ability is probably that it prevents one from being trapped by the terrain, allowing passage back and forth through obstacles... But how widely applicable it is remains unknown.
Sun Hang was a little curious whether this guy could pass through a high-voltage electrified wire mesh unscathed in his phantom state.
