Cao Weihua and the others were simply unable to comprehend the scene unfolding before them.
One of the attendants was busy exonerating himself, "It definitely wasn't the boxed meals' fault, our people didn't eat the boxed meals, and they still had an attack."
Another attendant, more inclined to think, said, "I've noticed that the people with the severe reactions are all those who threw stones. Could it be... could it be that they have offended the mountain god?"
His statement touched upon superstition, but strictly speaking... theoretically it was correct.
The chaos, of course, was caused by Feng Jun.
What means did he use? It was the "Bewitching Heart Poison Powder" from another plane.
The Yongyi Duke's Princely Heir once tried to use the poison powder against him but ended up having it confiscated by him.