Actually, as soon as he had ascended the mountain gate of the Da Guangming Sect, Gu Chen had sensed a persistent chill in the air that lingered and could not be waved away.
Although this chill was condensed and unyielding, it was extremely faint, such that others from the Jing Tian Department could hardly detect it.
However, having had extensive contact with demons and absorbed a great number of soul crystals, Gu Chen understood their power all too well, perhaps even better than Qin Wu in this respect.
Thus, upon arriving, Gu Chen had discovered it right away.
And this was also evidence that the Da Guangming Sect had pledged loyalty to the Six Union God Sect, so Gu Chen had always been on guard inwardly.
What Gu Chen hadn't expected, however, was that the Da Guangming Sect would choose to use poison.