The Hidden Moth Sect has a Stealth Skill, and other major Magic Sects each have techniques to conceal Divine Qi. Hilary is undoubtedly very adept at this. Given his current environment, it's indeed challenging to detect him using only Divine Sense.
But He Kao is different; he saw it directly with his "eyes."
The Yin Spirit floated over the upper part of the carriage space and saw Hilary but did not disturb him, maintaining a state of silence.
About twenty minutes later, Hilary chose a particularly crowded and chaotic station to get off the bus, carefully keeping his presence concealed along the way.
Though still cautious, he clearly breathed a sigh of relief, thinking he had safely escaped. Little did he know, once the Hidden Moth had marked someone secretly, it was nearly impossible to lose track of them.
After leaving the station, Hilary hailed a cab and headed towards the suburbs, with He Kao's Yin Spirit floating and tailing him from above.
